Question

Solve using elimination. 10x + y = -19 10x + 3y = -17

Answer 1

Subtract 10x

10x + y = -19

10x + 3y = -17

You would get:

-2y = -2

Two negatives make a positive number! Divide

y = 1

Plug in

10x + (1) = -19

10x = -20

Divide

x = -2

Your solutions are

x = -2

y = 1

Answer 2

we want to add the 2 equations to eliminate a variable

see which constants match

the x's both have 10

multiply the first equation by -1

-10x-y=19

add that to the 2nd equation

-10x-1y=19

10x+3y=-17 +

0x+2y=2

so 2y=2 -> y=1

subsitute to find other number

10x+y=-19

10x+1=-19

10x=-20

divide both sides by 10

x=-2

the solution is (x,y)=(-2,1)