If 9x4 + 12x3 + 28x2 + ax +b is a perfect square,find the values of a and b.

If $9 x^{4} + 12 x^{3} + 28 x^{2} + a x + b$ is a perfect square,
find the values of a and b.

Matching exercise

Match the items on the right to the items on the left.

Step - 1

Step - 2

Step - 3