Question 335624
1.{{{9x+7y=56}}}
2.{{{x=7}}}
Directly substitute eq. 2 into eq. 1,
{{{9(7)+7y=56}}}
{{{63+7y=56}}}
{{{7y=-7}}}
{{{y=-1}}}
.
.
.
({{{7}}},{{{-1}}})