solve please -3(x+2)< -15?
回答 (6)
2009-07-31 4:38 pm
✔ 最佳答案
= -3(x+2)< -15 (Distribute -3 to (x+2))= -3x - 6 < -15 (Transpose -6)
= -3x < -15 + 6
= -3x < - 9 (Divide both sides by -3)
= -3x/-3 < -9/-3
= x < 3
= x > 3 (Answer)
Since we divided an inequality by a negative, we must flip the inequality sign to get it right. Hope this helps.
2009-07-31 5:33 pm
-3(x + 2) < -15
x + 2 > -15/(-3)
x > 5 - 2
x > 3
x + 2 > -15/(-3)
x > 5 - 2
x > 3
2009-07-31 5:22 pm
The rule is that when you multiply an inequality by a negative
number, you have to reverse the direction.
-3(x+2)< -15 multiply by -1
3(x+2) > 15
Now divide both sides with 3
x+ 2 > 5
x > 5 -2
x > 3
number, you have to reverse the direction.
-3(x+2)< -15 multiply by -1
3(x+2) > 15
Now divide both sides with 3
x+ 2 > 5
x > 5 -2
x > 3
2009-07-31 4:38 pm
-3x -6 < -15
add 6 to both sides
-3x -6+6 < -15+6
-3x < - 9
divide both sides by 3
-x < -3
Therefore x > 3
(When you change the sign on both sides, the inequality sign will reverse.)
add 6 to both sides
-3x -6+6 < -15+6
-3x < - 9
divide both sides by 3
-x < -3
Therefore x > 3
(When you change the sign on both sides, the inequality sign will reverse.)
2009-07-31 4:37 pm
Divide both sides by 3, you get: -(x+2)<-5
Multiply both sides by minus 1 (it will reverse the direction of the inequality); you get x+2 >5
Subtract 2 from both sides, you get x > 3
Multiply both sides by minus 1 (it will reverse the direction of the inequality); you get x+2 >5
Subtract 2 from both sides, you get x > 3
2009-07-31 4:36 pm
-3x-6 < -15
-3x < -9
x < 3
-3x < -9
x < 3
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