Question 999643
{{{x + 5 y - 10 = 0}}}...1st eq.
{{{x = 2 y - 8}}}...2nd eq.
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make a substitution for x in the first equation

{{{(2y - 8) + 5y - 10 = 0}}}...1st eq....solve for {{{y}}}

{{{2y - 8 + 5y - 10 = 0}}}

{{{highlight(7y - 18  = 0)}}}=>the resulting equation in simplest form

to find the solutions to the system solve for {{{y}}}:

{{{7y - 18  = 0}}}

{{{7y= 18}}}

{{{highlight(y= 18/7)}}}=> exact solution

now go back to 2nd eq., substitute {{{y}}} and find {{{x}}}

{{{x = 2 (18/7) - 8}}}...2nd eq....write {{{8}}} as {{{56/7}}}

{{{x = 36/7 - 56/7}}}

{{{highlight(x = - 20/7)}}}