Question 707693
Equation 1: {{{B = A + 2}}}
Equation 2: {{{C = A + 4}}}
Equation 3: {{{A + 3B = 2C + 38}}}
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Note that B & C are written in terms of A. Substitute their values into equation 3.
Equation 3: {{{A + 3B = 2C + 38}}}
{{{A + 3*(A + 2) = 2*(A + 4) + 38}}}
Multiply through
{{{A + 3A + 6 = 2A + 8 + 38}}}
Combine like terms
{{{4A + 6 = 2A + 46}}}
Subtract 6 from both sides
{{{4A = 2A + 40}}}
Subtract 2A from both sides
{{{2A = 40}}}
Divide both sides by 2
{{{highlight(A = 20)}}}
Now plug 20 into equations 1 & 2 for A.
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Equation 1: {{{B = A + 2}}}
{{{B = (20) + 2}}}
{{{highlight_green(B = 22)}}}
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Equation 2: {{{C = A + 4}}}
{{{C = (20) + 4}}}
{{{highlight(C = 24)}}}