Let $\displaystyle{n}=\usepackage{cmbright}\Huge\$ the number of nickels and let $\displaystyle{d}=\usepackage{cmbright}\Huge\$ the number of dimes. Nickels are worth $0.05 and dimes are worth $0.10, so:

(A) $\displaystyle{n}+{d}={32}\usepackage{cmbright}\Huge\$ (B) $\displaystyle{0.05}{n}+{0.10}{d}={1.95}\usepackage{cmbright}\Huge\$

Solve (A) for n: $\displaystyle{n}={32}-{d}\usepackage{cmbright}\Huge\$

Substitute into (B): $\displaystyle{0.05}{\left({32}-{d}\right)}+{0.10}{d}={1.95}\usepackage{cmbright}\Huge\$

Multiply, and combine like terms: $\displaystyle{1.6}+{0.05}{d}={1.95}\usepackage{cmbright}\Huge\$

The solution of this equation is $\displaystyle{d}={7}\usepackage{cmbright}\Huge\$ , which gives you $\displaystyle{n}={32}-{7}={25}\usepackage{cmbright}\Huge\$ .