SOLUTION: I need to solve algebraically, then graph. Should I solve by elimination or substitution? Either way I'm running into a lot of mumbo jumbo. Your help and/or hints are greatly ap

Algebra ->  Systems-of-equations -> SOLUTION: I need to solve algebraically, then graph. Should I solve by elimination or substitution? Either way I'm running into a lot of mumbo jumbo. Your help and/or hints are greatly ap      Log On


   

Question 79579: I need to solve algebraically, then graph. Should I solve by elimination or substitution? Either way I'm running into a lot of mumbo jumbo. Your help and/or hints are greatly appreciated!
X^2 - 4Y^2 = 16
2Y - X = 2
Found 2 solutions by elektrisitee, Earlsdon:
Answer by elektrisitee(1) About Me  (Show Source):
You can put this solution on YOUR website!
use substitution making it x^2=4y^2+16
then you take the sqare root of the right side
so that x=2y+4
then, you plug x into the other equation.


Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve this system of equations: I would use substitution.
1) x%5E2-4y%5E2+=+16
2) 2y-x+=+2 Write this as:
2a) 2y+=+x%2B2 Now square both sides. 4y%5E2+=+x%5E2%2B4x%2B4 and substitute into equation 1).
x%5E2-%28x%5E2%2B4x%2B4%29+=+16 Remove the parentheses (Remember to change the signs of the terms inside the parentheses!)
x%5E2-x%5E2-4x-4+=+16 Simplify.
-4x-4+=+16 Add 4 to both sides.
-4x+=+20 Divide both sides by -4.
x+=+-5 Now substitute this into equation 2a) and solve for y.
2a) 2y+=+-5%2B2
2y+=+-3 Divide both sides by 2.
y+=+-3%2F2
The solution is: (-5, -3/2)
Check:
%28-5%29%5E2-4%28-3%2F2%29%5E2+=+25-4%289%2F4%29=25-9+=+16