solve each system by substution: y = 2x + 3 ; 4x + y = 8
thx so much to all who replied to my Q
2006-06-16 16:47:06 · 6 answers · asked by Anonymous in Education & Reference ➔ Homework Help
To solve by sustitution mean you chose one of the equations and solve for one of the unknowns. I this case, the first euqation already gives you the value of y. then, just substitute it into the other equation:
4x + (2x + 3) = 8
and solve for x.
6x + 3 = 8
6x = 5
x = 5/6
Now, go back to the first one to find y:
y = 2(5/6) + 3
y = 5/3 + 3 = 14/3
2006-06-16 17:23:05 · answer #1 · answered by kamelåså 7 · 2⤊ 0⤋
The 2 equations can also be written as
y - 2x = 3 ----(1)
4x + y = 8 ----(2)
now multiply eq(1) with 2
ie 2y - 4x = 6
and write the (2) eq as it is below it
2y - 4x =6
4x + y = 8 (4x and -4x will cancel each other)
----------------
3y=14
y=14/3
now substitute value of y in eq(1) and find the value of x
x=5/6
hope u did understand
2006-06-16 20:59:34 · answer #2 · answered by halleberry_aus 4 · 0⤊ 0⤋
y=2x+3
=4x=8-y
=x=8-y/4
=y=2(8-y/4)
=y=16-2y/4
=6y=16
=y=16/6
2006-06-16 22:51:25 · answer #3 · answered by Anonymous · 0⤊ 0⤋
x = -1/2
y = 2
2006-06-16 16:51:49 · answer #4 · answered by westervel 3 · 0⤊ 0⤋
it is x = -1/2 and y=2. dang grl what grade r u in! i think ur in 7th. i learned this stuff in 7 th grade. lol.
2006-06-16 17:50:24 · answer #5 · answered by me 2 · 0⤊ 0⤋
i think, not sure, y=x. then x=1 and y=4. could be could not be been a long time. hope its what your looking for.
2006-06-16 16:58:19 · answer #6 · answered by S. B 1 · 0⤊ 0⤋