Question 312545
um your first 2 sets of systems dont all have an equation please make sure u write the correct symbols 3x-y+3 and x-2y+1 ??

Solve using the substitution method
4x-y=7 : {{{-y=7-4x}}} : {{{y=-7+4x}}}
5x-8y=2 : {{{-8y=2-5x}}} : {{{y=-(2-5x)/8}}}
{{{(-2+5x)/8=-7+4x}}}
{{{(-2+5x)=-56+32x}}}
{{{(54+5x)=32x}}}
{{{54=27x}}}
{{{2=x}}}
{{{y=-7+4(2)}}}
{{{y=1}}}

x=5-y
2x+7y=0 : {{{2x=-7y}}} : {{{x=(-7/2)y}}}
{{{5-y=(-7/2)y}}}
{{{10-2y=-7y}}}
{{{10+5y=0}}}
{{{5y=-10}}}
{{{y=-2}}}
{{{x=5-(-2)}}}
{{{x=7}}}