N13 | Maths Made Easy

N13

QUESTION: Evaluate \dfrac{3}{7}-\dfrac{6}{5}.

 

ANSWER: To find a common denominator, multiply the denominators: 7\times 5=35. To make the denominator of the first fraction 35, we need to multiply its top and bottom by 5:

\dfrac{3}{7}=\dfrac{3\times5}{7\times5}=\dfrac{15}{35}

To make the denominator of the second fraction 35, we need to multiply its top and bottom by 7:

\dfrac{6}{5}=\dfrac{6\times7}{5\times7}=\dfrac{42}{35}

Now we can do the subtraction. We get:

\dfrac{15}{35}-\dfrac{42}{35}=-\dfrac{27}{35}