Don't mind what i wrote i am so confused:

The correct option is D.

Step-by-step explanation:

a = 9c²+4

b= 7+3c

Firstly solve 2nd equation for c in terms of b:

b=7+3c

b-7=3c

b-7/3 = c

Now substitute the value of c in equation 1:

a= 9c²+4

a=9(b-7/3)² +4

a=9(b-7)²/9+4

9 will be cancelled by 9, so the equation we get is:

a=(b-7)²+4

Apply whole square formula for (b-7)²

a=b²-14b+49+4

Solve like terms:

a=b²-14b+53

Therefore the correct option is D

answer: ouch. thats difficult

step-by-step explanation: