Determine which polynomial is a perfect square trinomial. 25x2 − 40x − 16 9a2 − 20a − 25 25b2 − 15b + 9 16x2 − 56x + 49

D) 16x^2 − 56x + 49

Step-by-step explanation:

It is 16x^2 - 56x + 49

(4x)^2 - 2*4x*7 + 7^2

This is in the form of (a - b)^2 = a^2 - 2ab + b^2

Here a = 4x and b = 7

(4x)^2 - 2*4x*7 + 7^2 = (4x - 7)^2

Therefore, answer is D) 16x^2 − 56x + 49

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Thank you.

= 5

step-by-step explanation:

to find the 15th term substitute n = 15 into the nth term formula

= (- 3 × 15 ) + 50 = - 45 + 50 = 5