Question 179435
I'm going to use the substitution method:



{{{4x-5y=12}}} Start with the second equation.



{{{4((4/5)y+12)-5y=12}}} Plug in {{{x=(4/5)y+12}}}



{{{(16/5)y+48-5y=12}}} Distribute



{{{16y+240-25y=60}}} Multiply EVERY term by the LCD 5 to clear out the fraction.



{{{-9y+240=60}}} Combine like terms on the left side.



{{{-9y=60-240}}} Subtract {{{240}}} from both sides.



{{{-9y=-180}}} Combine like terms on the right side.



{{{y=(-180)/(-9)}}} Divide both sides by {{{-9}}} to isolate {{{y}}}.



{{{y=20}}} Reduce.



Note: the value {{{y=20}}} is part of none of the solutions. So double check the answers or the problem itself.