Question

Help with this then I think I can do the rest

Answer 1

Help with only one question, then I will try the other one by myself

Answer 2

Which one do you want to do now?

Answer 3

@zarkam21 ^^^^ Which on now?

Answer 4

First one

Answer 5

y = 2x
x² + y² = 15
------------

These are the equations of a line and a circle.

We can expect 0, 1, or 2 answers.

Answer 6

In x² + y² = 15, substitute 2x for y because the first equation is y = 2x.

Answer 7

x² + (2x)² = 15

x² + 4x² = 15

5x² = 15

x² = 3

x = +√ 3 and x = - √ 3

Answer 8

For each of the two x values, solve for the corresponding y value in the first equation.

y = 2x

Let x = +√3

y = 2 * +√ 3 = 2 √3

Answer 9

y = 2x

Let x = - √3

y = 2 * - √3 = -2√3

Answer 10

Solution Coordinates are:

(√3 , 2 √3) and (- √3 , -2√3)

Answer 11

So the solutions are (√3 , 2 √3) and (- √3 , -2√3)

Answer 12

For the first problem

Answer 13

Here's a graph of our work.

Answer 14

See it "live" here:

http://www.wolframalpha.com/input/?i=y+%3D+2x,+x%C2%B2+%2B+y%C2%B2+%3D+15

Answer 15

>>> So the solutions are (√3 , 2 √3) and (- √3 , -2√3)

Yes

Answer 16

Oh okay thanks so much! =)

Answer 17

You are welcome.

Your problem (second one) is quite similar to this.

Answer 18

Yes, I got the answer for that one as well as a couple other ones. Thanks again for all of your help, I really appreciate it. =)