MyQuestionIcon

1

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

Definition of Functions

If f2x+3y,2...

Question

If $f (2 x + 3 y, 2 x - 7 y) = 20 x$ ,then $f (x, y)$ equal to

A

7 x - 3 y

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

B

7 x + 3 y

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

C

3 x - 7 y

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

D

x - y

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

Open in App

Solution

The correct option is C $7 x + 3 y$
In $f (2 x + 3 y, 2 x - 7 y) = 20 x$
Let $2 x + 3 y = X$ ...(1)
and $2 x - 7 y = Y$ ...(2)
Multiplying (1) by $7$ and (2) by $(3)$ we get
$14 x + 21 y = 7 X$ and $6 x - 21 y = 3 Y$
Adding them
$20 x = 7 X + 3 Y$
Hence
$f (X, Y) = 7 X + 3 Y$
or $f (x, y) = 7 x + 3 y$

Suggest Corrections

thumbs-up

0

Similar questions

f (2 x + 3 y, 2 x - 7 y) = 20 x

f (x, y)

f (2 x + 3 y, 2 x - 7 y) = 20 x

f (x, y)

x, y, z \in R

△ = ∣ ∣ ∣ ∣ \begin{matrix} x & x + y & x + y + z 2 x & 5 x + 2 y & 7 x + 5 y + 2 z 3 x & 7 x + 3 y & 9 x + 7 y + 3 z \end{matrix} ∣ ∣ ∣ ∣ = - 16

x

x, y, z \in R

Δ = ∣ ∣ ∣ ∣ \begin{matrix} x & x + y & x + y + z 2 x & 5 x + 2 y & 7 x + 5 y + 2 z 3 x & 7 x + 3 y & 9 x + 7 y + 3 z \end{matrix} ∣ ∣ ∣ ∣ = - 16

x

x

3 x + 7 y = 32

7 x + 3 y = 48

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Definition of Function

MATHEMATICS

Watch in App

explore_more_icon

Explore more

Definition of Functions

Standard XII Mathematics

Join BYJU'S Learning Program

CrossIcon