Question 944465
Expansion  of 3(2t-7)^2 can be done as below

We will first expand the quantity within the parenthesis 

Use the formula (a- b)^2 = a^2 - 2ab + b^2

3( 4t^2 - 28t + 49)

Finally applying Distributive property we get

12t^2 - 84t + 147 [Answer]