maths homework

(x+3)(x+5) = x² +5x+3x+15 = x² +8x+15 

Expand the following:
(x+3) (x+5)

(x+3) (x+5) = (x) (x) + (x) (5) + (3) (x) + (3) (5):
x x+5 x+3 x+3 5

x x = x^2:
x^2+5 x+3 x+3 5

3×5 = 15:
x^2+5 x+3 x+15

5 x+3 x = 8 x:
Answer: |x^2 + 8x + 15