Answer:
x = -8
Explanation:
Given the below system of equations;
[tex]\begin{gathered} x=2y-4\ldots\ldots\ldots\ldots\ldots\text{.Equation 1} \\ 7x+5y=-66\ldots\ldots\ldots\ldots\text{Equation 2} \end{gathered}[/tex]The solve the above, let's go ahead and put equation 1 into equation 2 and solve for y;
[tex]\begin{gathered} 7(2y-4)+5y=-66 \\ 14y-28+5y=-66 \\ 19y=-66+28 \\ 19y=-38 \\ y=-\frac{38}{19} \\ y=-2 \end{gathered}[/tex]To find x, we have to substitute the value of y into equation 1 and solve for x;
[tex]\begin{gathered} x=2(-2)-4=-4-4=-8 \\ x=-8 \end{gathered}[/tex]