2007-05-22 11:16:27 · 7 answers · asked by Anonymous in Education & Reference ➔ Homework Help
You know y = 2x -12. Substitute it for y in 3x + 3y = 9.
3x + 3(2x - 12) = 9
3x + 6x - 36 = 9
9x = 45
x = 5
Substitute 5 for x, and solve for y.
y = 10 - 12
y = -2
2007-05-22 11:30:01 · answer #1 · answered by bucknut71 2 · 0⤊ 1⤋
3y + 2Z = 12 y - z = 9. from the 2nd: y = z+9 replace into the 1st 3(z+9) + 2z = 12 3z + 27 + 2z = 12 5z + 27 = 12 subtract 27 from the two aspects 5z = -15 divide via 5 z = -3 y = z+9 = -3+9 = 6 the respond is C.
2016-11-26 02:13:34 · answer #2 · answered by ? 3 · 0⤊ 0⤋
3x + 3y =9
y = 2x - 12
so
3x + 3(2x - 12) = 9
3x + 6x - 36 = 9
9x - 36 = 9
9x = 45
x = 5
2007-05-22 11:23:01 · answer #3 · answered by frenchtoast88 2 · 0⤊ 0⤋
subsitute y for (2x - 12):
3x +3 (2x-12) =9
3x + 6x-36=9
add 36 on both sides:
3x +6x=45
solve for x:
9x=45
x=5
2007-05-22 11:27:00 · answer #4 · answered by crissy 1 · 0⤊ 1⤋
*Best answer
put y=2x-12 into 3x+3(2x-12)=9, 3x+6x-36=9, 9x-36=9, 45=9x, x=5
2007-05-22 11:25:24 · answer #5 · answered by misscalifornia 2 · 0⤊ 1⤋
slove this 3x+3(2x-12)=9
3x+6x-36=9
9x=45
x=9/45
2007-05-22 11:24:04 · answer #6 · answered by systematicalf 2 · 0⤊ 1⤋
3x+3(2x-12)=9
3x+6x-36=9
9x-36+36=9+36
9x=45
x=5
y=10-12
y=-2
2007-05-22 11:39:46 · answer #7 · answered by Dave aka Spider Monkey 7 · 0⤊ 1⤋