Question

A (×+1).(×+3)=
b (y-3).(y-2)=
c ((a+b).(a+b)=
d (×+3).(×+3)=​

Answer 1

Façamos a multiplicação dos parenteses:

a)(x+1).(x+3)=

x²+3x+x+3=

x²+4x+3=0

a=1

b=4

c=3 =>vamos encontrar o valor de delta:∆

∆=b²-4.a.c

∆=4²-4.1.3

∆=16-12

∆=4

Usaremos a fórmula de Bhaskara

x=-b±√∆/2.a

x=-4±√4/2.1

x=-4±2/2

x'=-4+2/2

x'=-2/2

x'=-1

x"=-4-2/2

X"=-6/2

x"=-3

S={-3,-1}

b)(y-3).(y-2)

y²-2y-3y+6

y²-5y+6=0

a=1

b=-5

c=6 ∆=(-5)²-4.1.6

∆=25-24

∆=1

y=-(-5)±√1/2.1

y=5±1/2

y'=6/2

y'=3

y"=4/2

y"=2

S={2,3}

c)(a+b).(a+b)=

a²+ab+ab+b²

a²+2ab+b²

d)(x+3).(x+3)

x²+3x+3x+9=0

x²+6x+9=0

a=1

b=6

c=9 ∆=6²-4.1.9

∆=36-36

∆=0

x=-6±√0/2.1

x=-6±0/2

x'=-6/2

x'=-3

x"=-6-0/2

x"=-6/2

x"=-3

S={±3}