[tex]p\%=\frac{p}{100}\\\\10\%=\frac{10}{100}=0.1\\\\10\%\ of\ \$100=0.1\cdot\$100=\$10\\\\The\ price\ after\ increase:\$100+\$10=\$110\\\\10\%\ of\ \$110=0.1\cdot\$110=\$11\\\\The\ price\ after\ decrease:\$110-\$11=\$99\\\\Answer:\\\underline{The\ price\ after\ these\ changes\ is\ equal\ \$99}[/tex]