Question 508915
{{{7+highlight(4(2a+15)) = -13}}} First apply the "distributive property" to the term in the red box:
{{{highlight(4(2a+15)) = (4*2a+4*15)}}}={{{highlight(8a+60)}}} so now you have:
{{{7+highlight((8a+60)) = -13}}} Now simplify the left side of the equation.
{{{67+8a = -13}}} Subtract 67 from both sides.
{{{8a = -80}}} Finally, divide both sides by 8.
{{{highlight_green(a = -10)}}}