5x-2y=12 ,7x+3y=11

2 answers

rewrite as
15x-6y = 36
14x+6y = 22
now add to get
29x = 58
x = 2
now use that to find y
There are several methods you can use to solve this system.

This is one of the methods.

Multiply first equation by 7

35 x - 14 y = 84

Multiply second equation by 5

35 x + 15 y = 55

Now:

35 x - 14 y = 84
-
35 x + 15 y = 55
_______________
35 x - 35 x - 14 y - 15 y = 84 - 55

- 29 y = 29

Divide both sides by - 29

y = - 1

Put this value in first equation.

5 x - 2 y =12

5 x - 2 • ( - 1 ) = 12

5 x + 2 = 12

Subtract 2 to both sides

5 x = 10

x = 10 / 5 = 2

The solution is:

x = 2 , y = - 1

You can write solution as ( 2 , - 1 )