Question

17x+23y =40 and 23 x + 17 y = 80, then x+y=______
A. 120
B. 40
C. 3
D. 80​

Answer 1

Question:

Fill in the blank with the correct option;

If 17x + 23y = 40 and 23x + 17y = 80 ,

then x + y = .

A. 120

B. 40

C. 3

D. 80

Answer:

Option (C) => 3 .

Given:

17x + 23y = 40

23x + 17y = 80

To find:

x + y = ?

Solution:

We have;

17x + 23y = 40 -----------(1)

23x + 17y = 80 ----------(2)

Adding eq-(1) and eq-(2) , we get ;

=> 17x + 23y + 23x + 17y = 40 + 80

=> (17x + 23x) + (23y + 17y) = 120

=> 40x + 40y = 120

=> 40(x + y) = 120

=> x + y = 120/40

=> x + y = 3

Clearly ,the value of the x + y is 3 .

Hence,

The answer is option (C) .

Thus;

If 17x + 23y = 40 and 23x + 17y = 80 ,

then x + y = 3 .

Answer 2

option c . 3

Add both given equation :

17x+23y=40

23x+17y=80

+__________

40x+40y=120

Now Take 40 common

40(x+y)=120

x+y=120/40

x+y=3

Hence the value of x+y is 3

soln refers to the attachment