If {(Χ,Υ)} is the solution set of 2Χ+3Υ=8 and 3Χ+2Υ=17 then the value of Χ+Υ is…

2x + 3y = 8 .... ×3
3x + 2y = 17 .... × 2


6x + 9y = 24
6x + 4y = 34
-------------------- -
5y = -10
y = - 2

2x + 3y = 8
2x + 3(-2) = 8
2x - 6 = 8
2x = 8 + 6 = 14
x = 7

x , y = 7 , -2

x + y
= 7 + (-2)
= 5

MATH 2 Junior High School

Pembahasan :
2x + 3y = 8 ——» 6x + 9y = 24
3x + 2y = 17 ——» 6x + 4y = 34

Eliminasi...
6x + 4y = 34
6x + 9y = 24
——————— (-)
-5y = 10
y = -2

Subs..
2x + 3y = 8
2x + 3(-2) = 8
2x - 6 = 8
2x = 14
x = 7

So...
The value of x + y is...
= 7 + (-2)
= 5