Question

Solve x2 – 5x – 1 = 0 using the Quadratic Formula. Find the exact solutions. Then approximate any radical solutions. Round to the nearest hundredth.

Answer 1

To get started see attached Quadratic Formula

Answer 2

what is your a, b, and c?

Answer 3

i am not sure

Answer 4

The general form of your equation is

Ax^2 + Bx + C = 0

A=1
B=-5
C=-1

Use those and put them into the equation that was linked... what do you get so far?

Answer 5

I plugged in the numbers for you. Just have to simplify now.

\[x = \frac{ -B \pm \sqrt{B^2 - 4*A*C} }{ 2*A } = \frac{ 5 \pm \sqrt{(-5)^2 -4 * 1 *(-1)} }{ 2 * 1 }\]

Answer 6

how do i get the correct symbols?

Answer 7

What do you mean exactly?

Answer 8

just add and multiply numbers

Answer 9

never mind i thought i need all the square and plus or minus symbols but i get it now XD

Answer 10

x=\[\frac{ 5 \pm \sqrt{29} }{ 2 }\]

right? or did i mess up

Answer 11

inside the square root: 25 + 4

Answer 12

yup thats it @DanJS thank you!

Answer 13

you're welcome, anytime

Answer 14

i think im doing it wrong i keep getting 6.35

Answer 15

oh on my answers it says divide by 2 not 4?

Answer 16

oh right, that was a typo on my part

Answer 17

but im still not getting the right answer

Answer 18

\[\frac{ 5 - \sqrt{29} }{ 2 } \approx -0.193\]

Answer 19

\[\frac{ 5 + \sqrt{29} }{ 2 } \approx 5.193\]

Answer 20

would i put the + or + first?

Answer 21

they are 2 separate solutions, one is plus the other is minus, like my above 2 posts

Answer 22

the graph crosses the x axis at 2 values, those satisfy the equation in the question

Answer 23

i found out the one answer had a -5 haha tricky tricky tricky thank you!

Answer 24

welcome, anytime