2007-10-21 12:18:04 · 3 answers · asked by amani h 1 in Science & Mathematics ➔ Mathematics
4(3x-3)-8x=-4
12x-12-8x=-4
4x-12=-4
4x=8
x=2
y=3(2)-3
y=6-3
y=3
2007-10-21 12:24:02 · answer #1 · answered by mustangs_r4me 2 · 0⤊ 0⤋
Just as it is called, you want to substitute one equation into the other, replacing one of the variables. Since the first equation already has y by itself, use this to substitute 3x - 3 into the other equation in place of the y
4y becomes 4(3x - 3)
4(3x-3) -8x = -4
12x- 12 -8x = -4
4x= 8
x = 2
Now go back to y = 3x -3 and replace the x with 2
y = 3(2) - 3 = 3
Solution: (2, 3)
2007-10-21 12:24:34 · answer #2 · answered by Linda K 5 · 0⤊ 0⤋
y=3x-3
4y-8x=-4
4(3x-3) -8x = -4 <-- Substituted 3x-3 for y
12x-12 -8x = -4
4x = 8
x =2
y = 3*2-3 = 3
2007-10-21 12:23:41 · answer #3 · answered by ironduke8159 7 · 0⤊ 0⤋