Question

Part 1: Solve each of the quadratic equations below. Show your work. (3 points)

x2 − 25 = 0 and x2 = 2x + 15

Part 2: Describe what the solution(s) represent to the graph of each. (2 points)

Part 3: How are the graphs alike? How are they different? (2 points)

Answer 1

@kausarsalley

Answer 2

@waterineyes

Answer 3

I can help for first part only...

Answer 4

ok... how do i solve them ?

Answer 5

\(x^2- 25\) = 0

Here you must know:

\[a^2 - b^2 = (a + b)(a-b)\]

So, above equation can be written as:

\[x^2 - 5^2 = 0\]

Now use that formula here..

Answer 6

(x + 5)(x - 5) = 0

Answer 7

@waterineyes

Answer 8

that is factored, but not solved...
x + 5 = 0 or x - 5 = 0
x = -5 x = 5

Answer 9

Yep, so you got x = 5 and x = -5..

Answer 10

ok and for the other one?

Answer 11

Now, in later case:

\(x^2 - 2x - 15\) = 0 Right??

Answer 12

Can you make factors of 15 which will add to give -2 and product to give -15 ??

Answer 13

x^2 = 2x + 15

Answer 14

how did u get x^2 - 2x - 15 = 0 ?

Answer 15

Subtract 2x from both the sides..

Then Subtract 15 from both the sides..

Answer 16

Getting??

Answer 17

oo ok

Answer 18

So, can you find what I have said??

Answer 19

3 and -5

Answer 20

Yep:

So you will get:

\[(x + 3)(x - 5) = 0\]

Find x here..

Answer 21

x = -3, x = 5

Answer 22

Yep..

So these are the solutions for x and answer for first part..

And I am weak at graphing part..

Answer 23

what about Part 2? those answers represent what?

Answer 24

Those represent that the parabola cuts x-axis at these positions, that are -5 and 5 for earlier case and 5 and -3 for later part..

Answer 25

im gonna send u a PM @waterineyes

Answer 26

sent it..