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#
#x=-5" or "x=3#
#"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#