The answer is

In the choices; the coefficients 21, 32 and 10 are not perfect squares.
Answer:
36
Step-by-step explanation:
Since BD is similar to GI, the ratio of the sides of the triangles is 27:3=9:1. This means that BC is 9 times larger than BH, or 4*9=36 units long. Hope this helps!
If you're not sure, begin by looking for any divisor that will divide into 24a^3c and 3a without leaving a remainder. Note that 3 is such a number, and a is another.
Factoring out 3a from 24a^3*c and 3a, we get 3a{8a^2*c, 1}
So the GCF is 3a.
Answer:
-9 = y
Step-by-step explanation:
-45=5y
Divide each side by 5 to isolate y
-45/5=5y/5
-9 = y