Question

Derek bought 6.00 worth of 21 cent stamps and 41 cent stamps.

Answer 1

we have the expression

$0.21s+0.41(s-2)=6.00$

Solve for s

that means ----> isolate the variable s

$0.21s+0.41s-0.82=6.00$

Combine like terms

$\begin{gathered} 0.62s=6.00+0.82 \\ 0.62s=6.82 \end{gathered}$

Divide by 0.62 both sides

$\begin{gathered} s=\frac{6.82}{0.62} \\ s=11 \end{gathered}$