Solve: 7/5 - 2/15 - 2/3 Using Fraction Subtraction

Video Solution

Solution Steps

00:00 Solve

00:02 We want to find the least common denominator

00:05 Therefore we'll multiply by 3 and 5 respectively to find the common denominator

00:08 Remember to multiply both numerator and denominator

00:22 Let's calculate the multiplications

00:40 Subtract under the common denominator

00:48 Calculate the numerator

00:54 Reduce the fraction as much as possible

01:00 Remember to divide both numerator and denominator

01:03 And this is the solution to the question

Step-by-Step Solution

Let's try to find the least common denominator between 5 and 15 and 3

To find the least common denominator, we need to find a number that is divisible by 5, 15, and 3

In this case, the common denominator is 15

Now we'll multiply each fraction by the appropriate number to reach the denominator 15

We'll multiply the first fraction by 3

We'll multiply the second fraction by 1

We'll multiply the third fraction by 5

$\frac{7\times3}{5\times3}-\frac{2\times1}{15\times1}-\frac{2\times5}{3\times5}=\frac{21}{15}-\frac{2}{15}-\frac{10}{15}$

Now let's subtract:

$\frac{21-2-10}{15}=\frac{19-10}{15}=\frac{9}{15}$

We'll divide both the numerator and denominator by 3 and get:

$\frac{9:3}{15:3}=\frac{3}{5}$