Question 700501
Let P = number of pennies
Let N = number of nickels
Equation 1: {{{0.01P + 0.05N = 1.12}}}
Equation 2: {{{2N = P}}}
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Substitute 2N into equation 1 for P.
Equation 1: {{{0.01P + 0.05N = 1.12}}}
{{{0.01*(2N) + 0.05N = 1.12}}}
Simplify
{{{0.02N + 0.05N = 1.12}}}
Combine like terms
{{{0.07N = 1.12}}}
Divide both sides by 0.07
{{{highlight(N = 16)}}}
Now plug 16 into equation 2 for N
Equation 2: {{{2N = P}}}
{{{2*(16) = P}}}
{{{highlight_green(32 = P)}}}
Johnny has 32 pennies and 16 nickels.