Question 740655: solving systems using substitution
x+4y=5
4x-2y=11
I can't figure out what am I suppose to do so please help. Found 2 solutions by rothauserc, josmiceli:Answer by rothauserc(4718) (Show Source):
You can put this solution on YOUR website! we are given the two equations
x+4y=5
4x-2y=11
and we are asked to solve for x and y
from the first equation we have x = 5 - 4y
substitute for x in the second equation and we have
4*(5-4y) - 2y = 11
20-16y-2y = 11
-18y = -9 and
y = 1/2 and x = 3 from equation 1
You can put this solution on YOUR website! This is how substitution works:
(1)
Subtract from both sides
(1)
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Plug this expression for into (2)
(2)
(2)
(2)
(2)
(2)
(2)
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Plug this result back into (1) or (2)
(1)
(1)
(1)
(1)
-------------
check the solutions,
(2)
(2)
(2)
(2)
OK
(1)
(1)
(1)
(1)
OK
