Question

Відомо, що
a+3b/b=2.
Знайдіть значення виразу
1) а/b.
2) 5a+3b/a

Answer 1

$\displaystyle\bf\\\frac{a+3b}{b} =2\\\\1)\\\\\frac{a}{b} +\frac{3b}{b} =2\\\\\\\frac{a}{b} +3=2\\\\\\\frac{a}{b} =2-3\\\\\\\boxed{\frac{a}{b} =-1}\\\\\\2)\\\\\frac{5a+3b}{a} =\frac{5a}{a} +\frac{3b}{a} =5+3\cdot \frac{b}{a} =5+3\cdot\frac{1}{\frac{a}{b} } =5+3\cdot\frac{1}{-1} =\\\\\\=5+3\cdot (-1)=5-3=2\\\\\\\boxed{\frac{5a+3b}{a} =2}$