Question

Match the missing term with the perfect square trinomial 9X^2+?+25

49
6x
36
30x

Answer 1

9x^2+t+25=(ax+b)^2

9x^2+t+25=a^2*x^2+2abx+b^2 so

a^2=9 so a=3

b^2=25 so b=5 then

t=2ab using a and b from above

t=2*3*5=30

So the missing term is 30x