Respuesta :
Answer:
-x^2 + 21x + 3.
Step-by-step explanation:
9x - (x – 3)(x + 1) + 10x
= 19x - (x^2 - 2x - 3)
= -x^2 + 2x + 19x + 3
= -x^2 + 21x + 3.
Answer:
9x - (x-3)(x+1) +10x
Solving (x-3)(x+1) first
it implies x(x+1) -3 (x+1)
= x^2 + x - 3x -3
= x^2 -2x - 3
return the result into the original question
it gives: 9x - ( x^2 -2x -3) +10x
expand
9x - x^2 +2x+3+ 10x
collect the like terms
- x^2 +21x +3
Step-by-step explanation: