SOLUTION
In this question, we want to get the value of x and y such that:
5x + 6y = 14 --------------- equ 1 x 3 = 15 x + 18 y = 42 ................. equ 3
3x + 5y = 7 .................. equ 2 x 5 = 15 x + 25 y = 35 ..................equ 4
Solving equ 3 and 4 , we need to evaluate equ 4 minus equ 3
15 x - 15 x + 25 y - 18 y = 35 - 42
0 + 7 y = -7
7 y = -7
Divide both sides by 7 , we have :
y = -1
Put the value of y = -1 in equ 1 , we have :
5 x + 6 y = 14
5 x + 6 ( -1 ) = 14
5 x - 6 = 14
5 x = 14 + 6
5x = 20
Divide both sides by 5 , we have:
x = 4
CONCLUSION : X = 4 , Y = -1