It's not the difference of squares, rather it is the square of a difference. That leaves a perfect square trinomial, which narrows your selection to two choices. An expression with 2 terms is not a trinomial, so that further narrows your selection. The appropriate choice is
... (4xy -3z)² = 16x²y² -24xyz +9z², a perfect square trinomial
_____
The expression you have in your problem statement has no z term, so none of the choices is applicable to that one.
7k/3 = 21
x 3 x3
7k = 63
/7 /7
k = 9
(7(9)/3 = 21 = 63/3 = 21 = 21 = 21)
Answer:
45 inches
Step-by-step explanation:
85-40=45
b=45
how I know?
use the formula c^2-a^2=b^2
85 being c, a being 40 and b being 45
