Question 300995
7x+8=78  Are you serious?

Ok,
Subtract 8 from each side:
{{{ 7x + highlight(8 - 8) = 78 - 8 }}}
7x = 70
divide each side by 7
{{{ cross(7)x/cross(7) = 70/7 }}}
<b>x = 10</b> & bob's your uncle!