Algebra 1 question Please help!?
Find the solution to each system of equations by substitution.
2x+y=11
y=4x-7
according to my book the answer is (3,5)
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so your equation would then be 2x+4x-7=11, solve for x.
then plug what you got for x, and solve for y.
substitute y in equation 1
2x+4x-7=11
so 6x = 18
so x=3
put x=3 in either of the 2 equations
y=4*3-7 = 5
y=4x-7, that`s 2, so, substitute that y=4x-7 into 1, to give one
eqn, and one unknown, as follows:
2x + y = 11, so,
2x + [4x-7] = 11,so,
2x + 4x – 7 = 11, so
6x = 18,
x = 3, and y, which = 4x-7= 12 -7 = 5. Hope this helps, Twiggy.
You know that y = 4x-7
Substitute that into the first equation and solve for x
2x + y = 11
2x + (4x – 7) = 11
6x – 7 = 11
6x = 18
x = 3
Now plug that back into one of the equations and solve for y.
y = 4x – 7
y = 4*3 – 7 = 12 – 7 = 5
So your answer is
(x,y) = (3,5)
