How do you evaluate \frac { 8} { 9} \cdot \frac { 6} { 7} - \frac { 1} { 5}896715?

1 Answer
May 14, 2017

59/10559105

Explanation:

Solve in order of PEMDAS. Multiply first:

8/9xx6/789×67

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

(2xx2xx2)/(3xx3) xx (3xx2)/(7)2×2×23×3×3×27

We can see that a 33 on the top and bottom cancel and we're left with:

(2xx2xx2xx2)/(3xx7)2×2×2×23×7

This evaluates to:

16/211621

Now we have to subtract:

16/21-1/5162115

We have to find a common denominator. Multiply 16/211621 by 5/555 and multiply 1/515 by 21/212121:

(16/21)(5/5) - (1/5)(21/21)(1621)(55)(15)(2121)

This becomes:

80/105-21/1058010521105

Now we can just subtract the numerators:

80-21=598021=59

So we get:

59/10559105