This is a problem of the sum of two cubes. So if we think of C ^2 ^3 and we think of two g ^2 ^3, then plugging this into our cube formula we get C ^2 + 2 G squared times C ^2 ^2, which would be C to the 4th. We multiply the two together and change the sign. So we're going to subtract two C ^2 g ^2 and then we square the last term 4G to the 4th. That all comes from knowing our cube formula that says a cube plus b ^3 = A + B times a ^2 minus AB plus b ^2.