Question 699148
The Set Up:
Let A = # of 5 peso bills
Let B = # of 10 peso bills.
Equation 1: {{{A + B = 29}}}
Equation 2: {{{5A + 10B = 225}}}
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Solution:
Solve equation 1 for one of the variables.
Equation 1: {{{A + B = 29}}}
{{{A = 29 - B}}}
Now plug (29 - B) into equation 2 for A
Equation 2: {{{5A + 10B = 225}}}
{{{5*(29 - B) + 10B = 225}}}
Simplify
{{{145 - 5B + 10B = 225}}}
Combine like terms
{{{145 + 5B = 225}}}
Subtract 145 from both sides
{{{5B = 80}}}
Divide both sides by 5
{{{highlight(B = 16)}}}
Now solve plug 16 into equation 1 for B and solve for A
{{{A = 29 - B}}}
{{{A = 29 - (16)}}}
{{{highlight_green(A = 13)}}}