Add or subtract as indicated.
-$\frac{3}{10 x}+\frac{9}{14 x^{2}}$

A) $\frac{108}{70 x^{2}}$

B) $\frac{12}{140 x^{2}}$

C) $\frac{3(7 x+15)}{70 x^{2}}$

D) $\frac{12}{10 x+14 x^{2}}$

Question

Add or subtract as indicated.
-$\frac{3}{10 x}+\frac{9}{14 x^{2}}$

A) $\frac{108}{70 x^{2}}$

B) $\frac{12}{140 x^{2}}$

C) $\frac{3(7 x+15)}{70 x^{2}}$

D) $\frac{12}{10 x+14 x^{2}}$

Quizplus · Accepted Answer

To add the fractions, find a common denominator, which is $70x^2$ (the least common multiple of $10x$ and $14x^2$). Convert each fraction to have this common denominator: $\frac{3}{10x} = \frac{3 \cdot 7x}{10x \cdot 7x} = \frac{21x}{70x^2}$ and $\frac{9}{14x^2} = \frac{9 \cdot 5}{14x^2 \cdot 5} = \frac{45}{70x^2}$. Adding these gives $\frac{21x + 45}{70x^2} = \frac{3(7x + 15)}{70x^2}$.

Add or Subtract as Indicated 310x+914x2\frac{3}{10 x}+\frac{9}{14 x^{2}}10x3​+14x29​ A) 10870x2\frac{108}{70 x^{2}}70x2108​ B) 12140x2\frac{12}{140 x^{2}}140x212​

Add or Subtract as Indicated $\frac{3}{10 x}+\frac{9}{14 x^{2}}$ A) $\frac{108}{70 x^{2}}$ B) $\frac{12}{140 x^{2}}$