A) x < 21
B) x < 19
C) x < -21
D) x < -19
Thank you.
2007-10-15 11:29:01 · 7 answers · asked by ketch 1 in Science & Mathematics ➔ Mathematics
answer is d
2007-10-15 11:36:59 · answer #1 · answered by Jasmine 1 · 0⤊ 0⤋
Honestly, just do the math.
3x-12>4x+7
so
subtract 3x from both sides
-12>x+7
subtract 7 from both sides
-19>x
when x = -18, 3(-18)-12 = -66 ... 4(-18)+7 = -65
-66>-65 ... false
when x = -19, 3(-19)-12 = -69 ... 4(-19)+7 = -69
-69>-69 ... false
when x = -20, 3(-20)-12 = -72 ... 4(-20)+7 = -73
-72>-73 ... true
D) x<-19
2007-10-15 18:41:39 · answer #2 · answered by Rob 2 · 0⤊ 0⤋
Distribute 3 through the parentheses on the left:
3x - 12 > 4x + 7
Subtract 3x from both sides:
-12 > x + 7
Subtract 7 from both sides:
-19 > x
Reverse the order to get x on the left (don't forget to flip the symbol too):
x < -19
Answer D:
2007-10-15 18:35:36 · answer #3 · answered by Puzzling 7 · 0⤊ 0⤋
firstly, distribute so that it is:
3x-12 > 4x + 7
than get x on one side of the problem, what you do to one side you must do to the other
3x-3x-12 > 4x - 3x + 7
-12 > x + 7
isolate x
-12 - 7 > x +7 -7
so
-19 > x rewrite it to
x < -19
so D
2007-10-15 18:34:54 · answer #4 · answered by Chris D 1 · 0⤊ 0⤋
3(x-4) > 4x+7
3x-12 > 4x+7
-4x +12 -4x +12
-x>19
-x/-1 19/-1
D) x<-19 sign changes bc you divide
2007-10-15 18:42:43 · answer #5 · answered by Bruce Bruce 1 · 1⤊ 0⤋
3x - 12 > 4x + 7
- 19 > x
x < - 19
OPTION D)
2007-10-16 06:23:42 · answer #6 · answered by Como 7 · 0⤊ 0⤋
plug and chug the given #'s in the answer
2007-10-15 18:38:18 · answer #7 · answered by hot rod 1 · 0⤊ 0⤋