How do you evaluate \frac { 8} { 9} \cdot \frac { 6} { 7} - \frac { 1} { 5}?

1 Answer
May 14, 2017

59/105

Explanation:

Solve in order of PEMDAS. Multiply first:

8/9xx6/7

Break down the numbers into smaller forms so we can see what we can cancel:

(2xx2xx2)/(3xx3) xx (3xx2)/(7)

We can see that a 3 on the top and bottom cancel and we're left with:

(2xx2xx2xx2)/(3xx7)

This evaluates to:

16/21

Now we have to subtract:

16/21-1/5

We have to find a common denominator. Multiply 16/21 by 5/5 and multiply 1/5 by 21/21:

(16/21)(5/5) - (1/5)(21/21)

This becomes:

80/105-21/105

Now we can just subtract the numerators:

80-21=59

So we get:

59/105