How do you simplify \frac{a-3}{7}\cdot \frac{21}{3-a}a37213a?

1 Answer
Jan 18, 2018

-3

Explanation:

(a-3)/7*21/(3-a)a37213a
First of all take minus common from 3-a
= [a-3]/7*21/-(a-3)a3721(a3)
Now simplify by dividing
= (1cancel(a-3))/(cancel7)*(3cancel21)/-(cancel(a-3))
Now you are left with three in the numerator and -1 in the denominator.
= 3/-1
Shift the negative sign to the numerator,
You get -3