Question

what number should be added to x²+6k to get (x+3)²? b) if 21²=400+40+k,then find k​

Answer 1

Step-by-step explanation:

a) x^2 + 6x + 9 - x²+6k = 9 has to be added.

b) (20 + 1)^2 = 400 + 40 + 1

k = 1

Answer 2

Answer:

9 should be added

b) k=1

Step-by-step explanation:

first question should be x²+6x

9 should be added to x²+6x to get (x+3)²

(20+1)²=400+2(20)(1)+1²