Question 251141
Problem: {{{9x-4(7x-8x)=x-3}}}


{{{9x-4(7x-8x)=x-3}}}
{{{9x+(-4*7x)+(-4*(-8x))=x-3}}}
{{{9x-28x+32x=x-3}}}
{{{(9-28+32)x=x-3}}}
{{{13x=x-3}}}
{{{13x-x=-3}}}
{{{12x=-3}}}
{{{x=-3/12}}}
{{{x=-1/4}}}  <--- this is the x value, not -4.


If x=-4, this is how it would turn out:
{{{9x-4(7x-8x)=x-3}}}
{{{9(-4)-4(7(-4)-8(-4))=(-4)-3}}}
{{{-36-4(-28+32)=-7}}}
{{{-36-4(4)=-7}}}
{{{-36-16=-7}}}
{{{-52=-7}}}  <--- we can see here x cannot equal to -4