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 <em>y = 5x -3</em>.
<em>y = 5x - 3 </em>|| subtract -5x on both sides from the equal sign
<em>5x + y = -3 </em>|| 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 <em>y</em> in the standard form equation.
<em>5x + y = -3 </em>
<em>5x + 3x + 9 = -3 </em>|| combine like terms
<em>8x + 9 = -3 </em>|| subtract 9 on both sides from the equal sign
<em>8x = 6</em> || divide by 8 on both sides from the equal sign
<em>x = 0.75</em> || final answer for x
Then for solving y, take any equation in y-intercept form and substitute with the <em>x </em>in the equation, which I'm going to use <em>y = 3x + 9</em> in this case.
<em>y = 3x + 9 </em>|| substitute with x
<em>y = 3 (0.75) + 9 </em>|| multiply 3 and 0.75
<em>y = 3.75 + 9 </em>|| add 3.75 and 9
<em>y = 12.75</em><em> </em>|| final answer for y
Thus, <em>x = 0.75</em> and <em>y = 12.75.</em>
