Question 175991
First Step.

-Isolate one variable for either equation.

{{{-5x+3y=8}}}
{{{3y=5x+8}}}    add 5x to both sides

{{{y=(5x+8)/3}}}  divide both sides by 3

Second Step.

-Plug in isolated variable into second equation.

{{{-9x + 5(5x+8)/3 = 14}}}
{{{-9x + (25x + 40)/3 = 14}}}  "foil" or multiply the second term
{{{(-27x+25x+40)/3=14 }}}  use common denomenator of 3. multiply {{{-9x*3}}}

{{{(-2x+40)/3 = 14 }}}  combine like terms and simplify

{{{-2x+40=42}}}
{{{-2x = 42-40}}}   subtract 40 from both sides
{{{-2x = 2}}}
{{{x = -2/2}}}   divide both sides by -2 and simplify
{{{x = 1 }}}