Question 54434: I need your help please.
Solve the following system by substitution. If a unique solution does not exist, state whether the system is inconsistent or dependent. 8x – 4y = 16 and y = 2x - 4
Answer by tiffanyc(9)   (Show Source):
You can put this solution on YOUR website! I'm assuming this is supposed to be solved without using matrices, if not, feel free to e-mail me and ill type up a new solution:
To solve by substitution, we need to isolate one variable and then plug the value of that variable into the second equation:
8x - 4y =16
y=2x-4
This is saying that x and y are the same numbers for both equations so we can plug the value of y (given in equation 2) into equation 1
8x -4(2x-4) =16
Multiply the coefficient of y through the brackets to get:
8x -8x +16 =16 so basically 16=16
This system is dependant, x could be either 0 or (1/2y+2)
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