Question

Solve the following system of equations. Enter the y-coordinate of the solution. Round your answer to the nearest tenth.

5x+2y=21
-2x+6y=-34

Answer 1

-3.8

Explanation:

Answer 2

`\sf 5x+2y=21`

`\sf -2x+6y=-34`

We could solve for 'x' in the 2nd equation and then plug that into the first equation for 'x' and solve for 'y':


`\sf -2x+6y=-34`

Subtract 6y to both sides:


`\sf -2x=-6y-34`

Divide -2 to both sides:


`\sf x=3y+17`

Plug in 3y + 17 for 'x' in the first equation:


`\sf 5x+2y=21`


`\sf 5(3y+17)+2y=21`

Distribute 5:


`\sf 15y+85+2y=21`

Combine like terms:


`\sf 17y+85=21`

Subtract 85 to both sides:


`\sf 17y=-64`

Divide 17 to both sides:


`\boxed{\sf y\approx -3.8}`

This is the y-coordinate of the solution.