For this case we have the following functions:

We must find
when
.
So:

We apply distributive property to the terms within parentheses taking into account that:

We add similar terms taking into account that different signs are subtracted and the sign of the major is placed:

Thus, we have to:

Then, with x = 2:

Equal signs are added and the same sign is placed.
Answer:

Hmm
(a+b)^2=(a+b)(a+b)=a^2+2ab+b^2
basically
for
ax^2+bx+c
it is a perfect trinomial when
b=2(√a)(√c)
remember to take both positive and negative roots into consideration
because
(a+b)^2=a^2+2ab+b^2 and
(a-b)^2=a^2-2ab+b^2
see each
first one
-70=2(9)(4)
-70=72
false
second
-90=2(8)(5)
-90=80
false
third
-72=(9)(4)
-72=72
false
but, the last one could be negative
(9x-4)^2 is factor
that is the answer
the answer is 81x^2-72x+16
You need to upload a picture of the statement or include it so we can see what it is
Answer:
±2 sqrt(3) =x
Step-by-step explanation:
12 - x^2 = 0
Add x^2 to each side
12 - x^2 + x^2 = x^2
12 = x^2
Take the square root of each side
±sqrt(12) = sqrt(x^2)
±sqrt(4*3) = sqrt(x^2)
±sqrt(4) sqrt(3) = x
±2 sqrt(3) =x