Question

Which number completes the perfect square trinomial?
x2 + 20x + ?
A. 40
B. 100
C. 25
D. 80

Answer 1

B

Answer 2

Thanks Tyler

Answer 3

Use the identity to think of it...
(a+b)^2 = a^2 +2ab + b^2
The last number = (2ab/2a)^2 , now, a=x ..2ab = 20x..

Answer 4

@Tyler1992 You should show your workings...

Answer 5

@Callisto & @Tyler1992 Thank you both for helping me I am not choosing a best answer on this one cuz i like both of yours

Answer 6

@PsYcHoEmOmAtH Give it to @Tyler1992 then :)