500/20 = 25kcal per piece
8 * 25 = 200kcal.....yes, he is able to have 8 pieces
Y=Mx+b (m is slope, b is y-intercept)
What you do is plug the numbers for each variable ur equation will look like 2(6)(-3)+4
lets solve it step by step 2(6)(-3)+4
12(-3)+4 then -36+4 and ur answer will be -32
4x^2+25=4x^2=-25=x^2=-25/4 has no solution. because, negative number do not live under radical except complex number