MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Quadratic Formula

If xy=20 an...

Question

If $x y = 20$ and $(x + y)^{2} = 70$ , then $x^{2} + y^{2}$ is equal to

A

25

No worries! We‘ve got your back. Try BYJU‘S free classes today!

B

35

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C

30

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

D

50

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C $30$
$(x + y)^{2} = x^{2} + y^{2} + 2 x y$

It is given that $(x + y)^{2} = 70$ and $x y = 20$

$\Rightarrow 70 = x^{2} + y^{2} + (2 \times 20)$

$x^{2} + y^{2} = 70 - 40$

$= 30$

Suggest Corrections

thumbs-up

0

Similar questions

x^{2} + y^{2} = 47

x y = \frac{19}{2}

then the value of

3 (x + y)^{2} + (x - y)^{2}

x y = b

\frac{1}{x^{2}} + \frac{1}{y^{2}} = a

{(x + y)}^{2}

x^{2} + y^{2} = 25, x y = 12

x, y =

x^{2} + y^{2} - x y = 3

y - x = 1

\frac{x y}{x^{2} + y^{2}}

x^{y} = y^{x},

(\frac{x}{y})^{\frac{x}{y}}

is equal to:

b) If

\frac{x}{y} = \frac{6}{5}

\frac{x^{2} + y^{2}}{x^{2} - y^{2}}

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Solving QE using Quadratic Formula

MATHEMATICS

Watch in App

explore_more_icon

Explore more

Quadratic Formula

Standard X Mathematics

Join BYJU'S Learning Program

CrossIcon