Question

alguém me ajuda?pfvr​

Answer 1

Resposta:

a) x²+7x+12=0

∆= 7²-4.1.12

∆= 49-48

∆=1

x= -7+-√1

-----------

2.1

x= -7+-1

--------

2

x'= -7+1

-------

x'= 6

----

2

x'= 3

x" = -7-1

------

2

x"= -8

----

2

x"= -4

S={ 3,-4}

b)x²- 6x + 8= 0

∆= 6²-4.1.8

∆= 36-32

∆=4

x=6+-√4

---------

2

x'= 6+2

------. x'= 8. x'= 4

2. ----

2

x"= 6-2. x"= 4. x"=2

------. -----

2. 2

S={ 4,2}

c)-x²+x+6=0

∆= 1²-4.(-1).6

∆= 1+24

∆=25

x= -1+-√25

------------

2.(-1)

x= -1+-5

---------

-2

x'= -1+5

------

-2

x'= 4

---

-2

x'= -2

x"= -1-5

-------

-2

x"= -6

-----

-2

x"= 3

S={-2,3}