CBSE > Class 09 > Mathematics | CBSE Board | Homework Help

Q. If x+y= -4 and xy= 2, then find the value of x^2+y^2..... Solve) given, x+y = -4 xy = 2 To find, x^2 +y^2 = ? Since, (x+y)^2= x^2 +y^2 +2xy ● Squaring on both the sides.... => (x+y)^2 = (-4)^2 => x^2 +y^2 +2xy = 16 ● since, xy = 2 => x^2 +y^2+ 2×2 = 16 => x^2 +y^2 +4 = 16 => x^2 +y^2 = 16-4 => x^2 +y^2 = 12 ....ans. Hope you get the right answer..

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Student Inquisitive 6 years ago

In question, I think its not ..X+4... it will be x+y...so that we can get the answer of x^2+y^2

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Padmini Kumar 6 years ago

64+1/16

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Find the median of all prime numbers between 20 and 40.

Posted by Gauri Saneja 6 years ago

CBSE > Class 09 > Mathematics

2 answers

Student Inquisitive 6 years ago

How to solve that question (Find the median....40)?

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Vyom Dubey 6 years ago

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When a number x is added to the following set of numbers 5,7,8,12,6,10 and 11, the mean is 9. Calculate the value of x

Posted by Gauri Saneja 6 years ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

Square of 14

Posted by Harsh Deodhar 6 years ago

CBSE > Class 09 > Mathematics

5 answers

Ankit Rajput 5 years, 11 months ago

196

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Pragya Singh 5 years, 11 months ago

169

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Iqbal Ahmad 5 years, 11 months ago

196

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Seema Chandel 6 years ago

Answer is 169

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Prisha Gupta 6 years ago

196

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is difference of two irrational is rational?

Posted by Priyanshu Pal 6 years ago

CBSE > Class 09 > Mathematics

1 answers

Yogita Ingle 6 years ago

S.No	Rational Numbers	Irrational Numbers
1	Numbers that can be expressed as a ratio of two number (p/q form) are termed as a rational number.	Numbers that cannot be expressed as a ratio of two numbers are termed as an irrational number.
2	Rational Number includes numbers, which are finite or are recurring in nature.	These consist of numbers, which are non-terminating and non-repeating in nature.
3	Rational Numbers includes perfect squares such as 4, 9, 16, 25, and so on	Irrational Numbers includes surds such as 2, 3, 5, 7 and so on.
4	Both the numerator and denominator are whole numbers, in which the denominator is not equal to zero.	Irrational numbers cannot be written in fractional form.
5	Example: 3/2 = 1.5, 1/ 6 =0.1666..	Example: √5, √11

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(A+B) (A+B)

Posted by Mahver Joshi 6 years ago

CBSE > Class 09 > Mathematics

1 answers

Yogita Ingle 6 years ago

(A+B) (A+B) = (A + B)² = A² + 2AB + B²

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Convert in p/q form 0.2

Posted by Anmol Singh 6 years ago

CBSE > Class 09 > Mathematics

2 answers

Yogita Ingle 6 years ago

0.2 = 2/10

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Deepak Rai 6 years ago

Sir , how can we obtained square of 7119

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2x + 5x = 9x

Posted by Tushar Malik 6 years ago

CBSE > Class 09 > Mathematics

0 answers

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Corresponding angles are equal????

Posted by Ishika Sardana 6 years ago

CBSE > Class 09 > Mathematics

2 answers

Yogita Ingle 6 years ago

If a transversal intersects two parallel lines, then each pair of corresponding angles are equal.

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Tushar Malik 6 years ago

Yes

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The floor of a rectsngular hall has a perimeter 250 m if the cost painting the four walls at the rate of RS 10 per m2 is 15000 find the height of hall

Posted by Raj Singh 6 years ago

CBSE > Class 09 > Mathematics

1 answers

Yogita Ingle 6 years ago

Perimeter of rectangular hall = 2(l + b) = 250 m
Total cost of painting = Rs.15000
Rate per m2 = Rs.10
Area of four walls = 2(l + b) h m2 = (250×h) m2
A/q,
(250×h)×10 = Rs.15000
⇒ 2500×h = Rs.15000
⇒ h = 15000/2500 m
⇒ h = 6 m
Thus the height of the hall is 6 m.

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how to remember the theorems of ln 8 quadrilaterals easily

Posted by Baby Hamsa 6 years ago

CBSE > Class 09 > Mathematics

2 answers

Student Inquisitive 6 years ago

For remembering the theorems, practise the theorems based questions and for quick review see pg.151 summary of chapter Quadrilaterals

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Student Inquisitive 6 years ago

Chapter8 Quadrilaterals Following are the basic concepts:- • Introduction - about what is quadrilaterals • Angle Sum Property of a □ - 360° •Types of □ - ▪square, rectangle, rhombus are llgm ▪kite is not a llgm •Properties of a llgm(prooving questions come) Th.8.1a diagonal divides it into two congruent ?s ▪Th.8 2-in llgm , opposites side are equal ▪Th.8.3- converse of Th.8.2 ▪Th.8.4- in llgm, opposite angles are equal ▪Th.8.5- converse of Th.8.4 ▪Th.8.6- diagonals bisect each other ▪Th.8.7- converse of Th.8.6 ▪Th.8.8- in llgm, pair of opposite sides are equal and parallel •Mid-point theorem- two theorems only ▪Th.8.9- line segment joining the midpoints of two sides of a ? is ll to the 3rd side ▪Th.8.10- converse of Th.8.9 YOU CAN GO THROUGH THIS WAY AND ALSO PRACTICE THE THEOREMS WITH EXERCISE QUESTIONS... & for overview U can follow pg.151 summary.. So that it can help U, Hope so...

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Douts in circle chapte in ncert book of maths

Posted by Sanya Bharti 6 years ago

CBSE > Class 09 > Mathematics

0 answers

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Dout circle

Posted by Sanya Bharti 6 years ago

CBSE > Class 09 > Mathematics

0 answers

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Lcm of 2no's is 1200.what will be HCF

Posted by Bharti Bulani 6 years ago

CBSE > Class 09 > Mathematics

0 answers

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What are important concepts in real numbers

Posted by Sruthy Shyju 6 years ago

CBSE > Class 09 > Mathematics

1 answers

Student Inquisitive 6 years ago

For important concepts in real numbers U can go through pg.27 of ncert book math class9th i.e. Summary portion... & for better preparation, practise questions like:- •how to represent rational as well as irrational numbers on number line •how to find rational as well as irrational b/w two real numbers •how to express irrational numbers in the form of p/q •rationalization of denominator • laws of exponents for real numbers..

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What is the formula for the (a-b)2

Posted by Nirmal Sm 6 years ago

CBSE > Class 09 > Mathematics