Question

Determine o valor de x na função f(x)=3x+5x-2 sabendo que f(x)=0

Answer 1

f(x)=0 logo

0=3x²+5x-2
∆=b²-4ac
∆=5²-4.3.-2
∆=25-12.-2
∆=25+24
∆=49

x=-b±√∆/2a
x=-5±√49/2.3
x=-5±7/6

x'=-5+7/6
x'=2/6
x'=1/3

x''=-5-7/6
x''=-12/6
x"=-2