Question

Solve the system of the linear equation by adding or subtracting.

7x - y = 9
7x + 2y = 24

Answer 1

first equation by -1 and add to 2nd equaton


-7x+y=-9
7x+2y=24 +
0x+3y=15

3y=15
divide by 3 both sides
y=5

sub back
7x-y=9
7x-5=9
add 5 both sides
7x=14
divide by 7 both sides
x=2


x=2
y=5
(2,5)