CameraIcon

SearchIcon

MyQuestionIcon

1

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

Algebraic Identities

If x + y = ...

Question

If $x + y = 5, x^{3} + y^{3} = 35$ , then $x - y$ is equal to

A

0

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

B

\pm 1

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

C

5

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

D

30

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

Open in App

Solution

The correct option is C $\pm 1$
$(x + y)^{3} = x^{3} + y^{3} + 3 x y (x + y)$
or $5^{3} = 35 + 3 x y (5)$
or $125 - 35 = 15 x y$
or $x y = \frac{90}{15} = 6$
Now, $(x - y)^{2} = (x + y)^{2} - 4 x y$
$= 5^{2} - 4 \times 6$
$= 25 - 24 = 1$
$∴ x - y = \sqrt{1} = \pm 1$

Suggest Corrections

thumbs-up

0

Similar questions

x + y - 1 = 0

x^{3} + y^{3} - 1

\frac{x}{y} + \frac{y}{x}

\neq

x^{3} + y^{3}

+3xy(x + y) is equal to:

x + y = 5

x^{2} + y^{2} = 111

, then value of

x^{3} + y^{3}

\frac{x}{y} + \frac{y}{x} = - 1, (x, y \neq 0)

, then value of

x^{3} - y^{3}

y + \frac{y^{3}}{3} + \frac{y^{5}}{5} + . . . \infty = 2 [x + \frac{x^{3}}{3} + \frac{x^{5}}{5} + . . . \infty]

, then the relation between

x

y

x^{2} y = a x - y

2 a + 1

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Algebraic Identities

MATHEMATICS

Watch in App

explore_more_icon

Explore more

Algebraic Identities

Standard IX Mathematics

Join BYJU'S Learning Program

CrossIcon