Question 698281
Equation 1: {{{A + B = 143}}}
Equation 2: {{{A - B + 136 = 143}}}
Solve equation 1 for one of the variables
Equation 1: {{{A + B = 143}}}
{{{A = 143 - B}}}
Plug (143 - B) into equation 2 for A
Equation 2: {{{A - B + 136 = 143}}}
{{{(143 - B) - B + 136 = 143}}}
Combine like terms
{{{279 - 2B = 143}}}
Add 2B to both sides
{{{279 = 143 + 2B}}}
Subtract 143 from both sides
{{{136 = 2B}}}
Divide both sides by 2
{{{highlight(68 = B)}}}
Plug 68 into equation 1 for B
Equation 1: {{{A + B = 143}}}
{{{A + (68) = 143}}}
Subtract 68 from both sides
{{{highlight_green(A = 75)}}}