C
If you plug in the values in that equation, it works.
Answer:
answer B is correct of this question
Answer:
Error in the third line.
Step-by-step explanation:
There is an error in the third line.
We are dividing through by 7 but mx is not divided by 7.
Correct solution is:
mx + 7nx =7
x(m + 7n) = 7
x = 7 / (m + 7n).
Answer:
(2p+9)^2
Step-by-step explanation:
We know this is a perfect square trinomial
a^2 +2ab +b^2 = (a+b)^2
a = 2p b = 9
a^2 = 4p^2
2ab = 2*2p*9 = 36p
b^2 = 81
Check
4p^2 +36p+81 = (2p+9)^2
