Answer:
17. x =18
23. n =0.84
Step-by-step explanation:
17.
[tex]\frac{6}{5} = \frac{x}{15} \\\\\frac{x}{15}=\frac{6}{5}\\\\\mathrm{Multiply\:both\:sides\:by\:}15\\\\\frac{15x}{15}=\frac{6\cdot \:15}{5}\\\mathrm{Simplify\:}\frac{15x}{15}:\quad x\\\\\mathrm{Simplify\:}\frac{6\cdot \:15}{5}:\quad 18\\\\x=18\\[/tex]
23.
[tex]\frac{2}{0.21}=\frac{8}{n}\\\\ \mathrm{Apply\:fraction\:cross\:multiply:\:if\:}\\\frac{a}{b}=\frac{c}{d}\mathrm{\:then\:}a\times \:d=b\times \:c\\\\2n=0.21\times \:8\\\\\mathrm{Simplify\:}0.21\times \:8:\quad 1.68\\\\2n=1.68\\\\\mathrm{Divide\:both\:sides\:by\:}2\\\\\frac{2n}{2}=\frac{1.68}{2}\\\\Simplify\\\\n=0.84[/tex]
