|
Question 101436: Hello out there,I really need some help with some tough problems,the first one is,Solve the system of linear equations by graphing:4x-y=6 and 3x+y=1.The next one is,Use substitution to solve : 2x+y=7 and 5x-2y=4.The third one is,Use substitution to solve: x=3y-2 and 2x+4y=16.And the last one is,Find the solution of the system y=x^2+5 and y=2x+4.Thanks to whoever can help.
Answer by vertciel(183)   (Show Source):
You can put this solution on YOUR website! Hello there,
1. Graph 4x - y = 6 and 3x + y = 1
I recommend reading http://www.purplemath.com/modules/graphlin.htm first. This should help.
2. 2x + y = 7 and 5x - 2y = 4
We'll substitute in y since it is easier.
2x + y = 7
y = 7 - 2x
Substitute y into 5x - 2y = 4:
5x - 2(7 - 2x) = 4
5x - 14 + 2x = 4
3x = 18
x = 6
Therefore, y = 7 - 2(6)
= -5
3. x = 3y - 2 and 2x + 4y = 16
Try it yourself. See if you can solve this from question 2.
4. y = x^2 + 5 and y = 2x + 4
You can just set these equations equal to each other because they both equal y.
x^2 + 5 = 2x + 4
x^2 - 2x + 1 = 0
Do you know how to solve equations with a square power?
If not, you can graph the two equations and find the point of intersection.
|
|
|
| |
