Question 762688
Equation 1: {{{A + B + 15 = 2A}}}
Equation 2: {{{A - B + 5 = 2B}}}
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First you need to solve one of the equations for one variable.
I chose the second equation.
Equation 2: {{{A - B + 5 = 2B}}}
Add B to both sides.
{{{A + 5 = 3B}}}
Subtract 5 from both sides.
{{{A = 3B - 5}}}
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Now plug (3B - 5) into equation 1 for A.
Equation 1: {{{A + B + 15 = 2A}}}
{{{(3B - 5) + B + 15 = 2*(3B - 5)}}}
Simplify.
{{{3B - 5 + B + 15 = 6B - 10}}}
Combine like terms.
{{{4B + 10 = 6B - 10}}}
Subtract 4B from both sides.
{{{10 = 2B - 10}}}
Add 10 to both sides.
{{{20 = 2B}}}
Divide both sides by 2.
{{{highlight(10 = B)}}}
Now plug 10 in for B and solve for A.
{{{A = 3B - 5}}}
{{{A = 3*(10) - 5}}}
{{{A = 30 - 5}}}
{{{highlight_green(A = 25)}}}