looking at an example i jotted off the white board today,

C = 550 - 10X + (1/2)X^2

R = 75X - (1/2)X^2

Then Ive written P= R - C which is...

P = 85X - X^2 - 550

but i just jotted the answer, i get how ive got 85x but cant remember how to get the 1/2 x^2 into just -x^2

if someone could go throught the question that would be great,

Thank you.