Question

Check my answers again Lol please

Find the number of real number solutions for the equation.
x^2-15=0
1
0
2 - my answer
Can not be determined from the graph

Answer 1

are u sure its x^2-15=0 o.O ?

Answer 2

Use the quadratic formula to solve the equation. If necessary, round to the nearest hundredth.

A rocket is launched from atop a 101-foot cliff with an initial velocity of 116 ft/s.
a. Substitute the values into the vertical motion formula h = -16t^2 + vt + c. Let h = 0
b. Use the quadratic formula find out how long the rocket will take to hit the ground after it is launched. Round to the nearest tenth of a second.

A) 0 = -16t^2+101t+116; 8s
B) 0 = -16t^2+116t+101; 0.8s - my answer
C) 0 = -16t^2+101t+116; 0.8s
D) 0 = -16t^2+116t+101; 8s

Answer 3

\[ x^2-15=0 \\ x^2= 15 \\ x= \pm \sqrt{15} \]
you would not get real number solutions if you had to take the square root of -15
but here, you have two real numbers.

Answer 4

wait a min let me recheck

Answer 5

Yeah @dinamix

Answer 6

cuz i find answer like @phi

Answer 7

you have the correct equation, but if we used t=1 (which is close to t=0.8) we get
-16+116+101 which is not close to zero (we want height = 0 when on the ground)

Answer 8

I don't get it, are my answers wrong..

Answer 9

can you help me @ASAAD123

Answer 10

@pooja195

Answer 11

and one more question
Use any method to solve the equation. If necessary, round to the nearest hundredth.
7x^2-16x=8
0.42, –2.71- my answer
35.43, –33.14
5.42, –2.95
2.71, –0.42

Answer 12

the first one is correct.
The equation is correct for the second one. The solution isn't.
The third one is wrong

Answer 13

I wasn't sure.. for the second one I was like either B or C are both wrong.. if not B then C, not sure tho @peachpi

Answer 14

the equation you selected is the right one, but 0.8 isn't a solution to it. Check to see that you plugged the numbers into the quadratic equation correctly.

Answer 15

the third one is it D?

Answer 16

@peachpi

Answer 17

@Luigi0210

Answer 18

Can someone helpp meee

Answer 19

which question?

Answer 20

and one more question
Use any method to solve the equation. If necessary, round to the nearest hundredth.
7x^2-16x=8
0.42, –2.71- my answer
35.43, –33.14
5.42, –2.95
2.71, –0.42 - my answer

Answer 21

D

Answer 22

not A

Answer 23

so we are trying to find solution to \[7x^{2}-16x=8\] ?

Answer 24

so which method did you use to solve this question?

Answer 25

you could use, graphical methods, quadratic formula, etc..

Answer 26

yes D