Cecilia – GufoSaggio

Come risolvi $x ^ 2 + 2x – 15 = 0$ ?

Dicembre 20, 2019

Come risolvi $x ^ 2 + 2x – 15 = 0$ ? Risposta: $x=-5″ or “x=3$ Spiegazione: $”the factors of – 15 which sum to + 2 are + 5 and – 3″$ $rArr(x+5)(x-3)=0$ $”equate each factor to zero and solve for x”$ $x+5=0rArrx=-5$ $x-3=0rArrx=3$