solve by substitution method
7x + y = 18
11x + 3y = -6
A (26, 19)
B (-14, -34)
C (-8, 32)
D (6, -24)
E (-39, -29)
F (-34, -11)
2007-07-04 14:48:04 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Multiply the top equation by -3, add it to the second equation so the y's cancel and solve for x. You will get 6 for x. This corresponds to answer D.
2007-07-04 14:56:47 · answer #1 · answered by snwhte76 2 · 0⤊ 0⤋
7x + y = 18 subtract 7x from each side
y=18-7x
11x + 3y = -6 substitute 18-7x for y
11x+3(18-7x)=-6 distribute 3
11x+54-21x=-6 subtract 54 from each side
-10x=-60 divide both sides by -10
x=6
y=18-7x substitute 6 for x
y=18-7*6
y=18-42
y=-24
(6, -24)
D (6, -24)
is correct
2007-07-04 22:24:34 · answer #2 · answered by yupchagee 7 · 0⤊ 0⤋
y = 18 - 7x
11x + 3.(18 - 7x) = - 6
11x + 54 - 21 x = - 6
60 = 10x
x = 6
42 + y = 18
y = - 24
ANSWER D
2007-07-08 18:12:44 · answer #3 · answered by Como 7 · 0⤊ 0⤋
D
2007-07-04 21:56:50 · answer #4 · answered by Anonymous · 0⤊ 0⤋