I'm wondering if someone can help me as to why if this binomial was squared 2(3x-4)^2-3 it would equal 2(9x^2-24x+16)-3. It was in the practice and

I'm wondering if someone can help me as to why if this binomial was squared 2(3x-4)^2-3 it would equal 2(9x^2-24x+16)-3. It was in the practice and I've tried figuring it out but can't for some reason. It's probably something small I'm missing too.