Como você resolve x ^ 2 + 2x - 15 = 0 ?

Responda:

x=-5" or "x=3

Explicação:

"the factors of - 15 which sum to + 2 are + 5 and - 3"

rArr(x+5)(x-3)=0

"equate each factor to zero and solve for x"

x+5=0rArrx=-5

x-3=0rArrx=3