Answer:
6d^2 - 8d
Step-by-step explanation:
Multiply 2d to the other two monomials
4 + 2x = 7
2x = 7 - 4 = 3
x = 3/2 = 1.5 inches
BD is right but PA is wrong, would be BD and MK.
It opens upward when X is an even power. It would be for X squared or X raised to the 4th power.