Question

x-intercept of (2x+7)(x-1)

Answer 1

Find out where the numerator is equal to zero

Answer 2

Assuming that you mean y = (2x+7)(x-1), set y to 0 and determine which values of x give that value.

Answer 3

For example, the x-intercepts of the equation y = (x+a)(x-b) would be -a and b.

Answer 4

hmm. I've tried to put in -7, 1 and 7, -1 and 7,1

Answer 5

I'm really confused with this problem. Its really long and doesn't tell me if anything is wrong or right along the way. can i attach and you look?

Answer 6

Since it's (2x+7), not (x+7), the x-intercept will not be -7.

Answer 7

Think of it this way- if 2x + 7 = 0, what is the value of x?

Answer 8

7?

Answer 9

7/2?

Answer 10

Not exactly, but close. Solve it like you would any other equation:
\[2x+7 = 0\]\[2x = -7\]\[x = \frac{ -7 }{ 2 }\]

Answer 11

Then, you do the same with the other part of the factored equation- what is x in x - 1=0?

Answer 12

1

Answer 13

So you have your x-intercepts then :)

Answer 14

can you look at the attachment? it says the problem is wrong still. idk what is wrong though

Answer 15

You're telling them that the intercepts are 7 and -1, not -7/2 and 1

Answer 16

yea, i changed that part but it says its still wrong

Answer 17

Maybe you have to put it in the form (x, 0)

Answer 18

Or try putting it in decimal form.

Answer 19

wont allow decimals.

Answer 20

i have no idea

Answer 21

I know it's right though, try graphing it: https://www.desmos.com/calculator

Answer 22

well that part of the problem is right because the percentage i have went up

Answer 23

but something else is wrong and idk what

Answer 24

Looks all right to me. Must be the applet acting up.

Answer 25

No wait.

Answer 26

Maybe you're suppsoed to put the domain as [-inf, inf]?

Answer 27

i dont think so. in the example it says to put it in as (-inf, inf)

Answer 28

Well, either something's slightly off about the way you're imputting your answers, or the applet's messed up, because the answers are right.

Answer 29

it might be the site because theres another problem that i'm almost positive is right

Answer 30

this one