Question

x . (x+3) - 40 = 0

com resolução por favor !

#PiorMatéria

Answer 1

x(x+3)-40=0
x²+3x-40=0
a=1 b=3 c=-40
Δ=b² -4.a.c
Δ=3² -4.1.-40
Δ=9+160
Δ=169

x'=-b+√Δ/2a
x'=-3+13/2.1
x'=10/2=5

x"=-b-√Δ/2a
x"=-3-13/2.1
x"=-16/2
x"=-8