Question

What is the solution to the system below {5x+6y=143x+5y=7

Answer 1

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