With all those parantheses, your equation can get a little confusing. It can be rewritten like this: [4(2)(-5)-4^2]/(4*2). If you know PEMDAS, Parantheses, Exponenets, Multiplication, Division, Addition, Subtraction, you do the parantheses first, but within the parantheses you do exponents first, so [4(2)(-5)-16]/(4*2), then multiplication... [-40-16]/(8) so -56/8 which is -7.