Can anyone help me solve a maths expression?

Well,

(x+1)(x-2)(x+3) = (x+1)[x(x + 3) - 2(x + 3)]

= (x+1)[x^2 + 3x - 2x - 6]

= x*[x^2 + x - 6] + 1*[x^2 + x - 6]

= x^3 + x^2 - 6x + x^2 + x - 6

= x^3 + 2x^2 - 5x - 6

hope it' ll help !!

(x+1)(x^2+x-6)
= x^3+x^2-6x+x^2+x-6
= x^3+2x^2-5x-6

(x+1)(x-2)(x+3)
=(x^2+x-2x-2)(x+3)
=(x^2-x-2)(x+3)
=x^3+3x^2-x^2-3x-2x-6
=x^3+2x^2-5x-6

1st (x+1)(x-2)=(x^2-x-2) multiply this result withx+3
x^3-x^2-2x+3x^2-3x-6 simplifyx^3+2x^2-5x-6

foil twice