## Algebra 1

Use cross multiplication to solve for b. $\frac{3}{b}=\frac{7}{8-b}\longrightarrow$ cross multiply $3(8-b)=7b\longrightarrow$ multiply using distributive property $24-3b=7b\longrightarrow$ add 3b to each side $24-3b+3b=7b+3b\longrightarrow$ add $24=10b\longrightarrow$ multiply each side by 10 $\frac{24}{10}=\frac{10b}{10}\longrightarrow$ reduce $\frac{12}{5}=b$