expand and simplify: (5x^2 + 1)(2x+3)-2x(5x^2 - 3). Show your working
(5x^2 + 1)(2x+3)-2x(5x^2 - 3)
= 10x^3 +15x^2 +2x +3 -10x^3 +6x
= 15x^2 +8x +3
Working:
(5x^2 + 1)(2x+3)
= (5x^2)(2x) + (5x^2)(3) + (1)(2x) + (1)(3)
= 10x^3 +15x^2 +2x +3
-2x(5x^2 - 3)
= -2x(5x^2) +2x(3)
= -10x^3 +6x
Thus, combining the like terms, we get
(5x^2 + 1)(2x+3)-2x(5x^2 - 3) = 15x^2 +8x +3