Question

Complete the table by providing justification for each step of the proof.
Conjecture: If 4(x^2-2)=28, then xis 3 or -3

Answer 1

@Vocaloid

Answer 2

may I see the table?

Answer 3

im trying to get it

Answer 4

@Vocaloid

Answer 5

any ideas on the firs step?

Answer 6

plug in x

Answer 7

no, i mean on the table

Answer 8

no idea

Answer 9

note: the first step on the table is just the problem copied down, so we write "given"

Answer 10

any ideas on the second row?

Answer 11

ohh so its just words describing what they are?

Answer 12

yes, it's words describing how to go from the previous step to the next step

Answer 13

ohh ok

Answer 14

is 2 simplified?

Answer 15

so for step 2, what rule do we use to go from

4(x^2 - 2) to 4x^2 - 8?

Answer 16

hint: it's called the ________ Property

what word goes into the blank?

Answer 17

distributive?

Answer 18

very good!

Answer 19

so for step 2 we can write distributive property

Answer 20

any ideas for step 3?

Answer 21

hint: it's called the ______ Postulate

Answer 22

ohh i wont know that one

Answer 23

when we add the same thing to both sides, we call it the Addition Postulate

Answer 24

to go from 4x^2 - 8 = 28
to 4x^2 = 36, we add 8 to both sides

Answer 25

with me so far?

Answer 26

yes

Answer 27

there are also multiplication, division, subtraction postulates that work the same way

Answer 28

so addition postulate?

Answer 29

good! that's step 3

Answer 30

any ideas on 4?

Answer 31

simplified

Answer 32

not quite

Answer 33

what do we do to go from

4x^2 = 36

to x^2 = 9?

Answer 34

is it addition, subtraction, division, or multiplication?

Answer 35

division

Answer 36

good, so it's the division postulate

Answer 37

step 5 would just be "taking the square root"

I don't think it has a special name

Answer 38

how about simplified?

Answer 39

i'm not sure

Answer 40

"simplify by taking the square root?"

Answer 41

hm

Answer 42

ill put that... teacher wont mind