Question

Find x if f(x) = 2x + 7 and f(x) =-1

Answer 1

5

Answer 2

Replace f(x) with -1

f(x) = 2x + 7

-1 = 2x + 7

Answer 3

jk, its -4 sorry.

Answer 4

Now solve for x

-1 = 2x + 7

-1-7 = 2x + 7-7 ... Subtract 7 from both sides.

-8 = 2x

2x = -8

what's the next step?

Answer 5

I don't know, I'm confused with this stuff

Answer 6

2x means 2 times x

Answer 7

when we have 2x = -8, we divide both sides by 2 to isolate x

we divide to undo the multiplication of 2 to x

Answer 8

2x = -8

2x/2 = -8/2

1x = -4

x = -4

Answer 9

So it's -4?

Answer 10

correct

Answer 11

Thanks :)

Answer 12

you're welcome

Answer 13

-1=2x+7
2x=-1-7=-8
x=-4

Answer 14

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