First, when solving for x, you would need to make one of the equation into standard form, which would be Ax + By = C. So, I'm going to use y = 5x -3.
y = 5x - 3 || subtract -5x on both sides from the equal sign
5x + y = -3 || there you have one equation in standard form
Now, all you have to do now is substitute the y-intercept form equation into the standard form equation. As you can see, you would substitute the y-intercept form into the y in the standard form equation.
5x + y = -3
5x + 3x + 9 = -3 || combine like terms
8x + 9 = -3 || subtract 9 on both sides from the equal sign
8x = 6 || divide by 8 on both sides from the equal sign
x = 0.75 || final answer for x
Then for solving y, take any equation in y-intercept form and substitute with the x in the equation, which I'm going to use y = 3x + 9 in this case.
y = 3x + 9 || substitute with x
y = 3 (0.75) + 9 || multiply 3 and 0.75
y = 3.75 + 9 || add 3.75 and 9
y = 12.75 || final answer for y
Thus, x = 0.75 and y = 12.75.
