Can you solve -0.9x < -72?

divide by - 0.9 u get:

x > 72/ 0.9

x > 80

-0.9x < -72 (divide both sides by -0.9 and flip the inequality sign)
x > 80 <===ANSWER

You always flip the inequality sign whenever you multiply or divide by a negative value.

First, you have to divide each side by -0.9 to isolate x.
x<80

Then, you have to switch the sign because you're dividing by a *negative*. (This is also true when multiplying a negative, as well.)

x>80

Voila! There's your answer.

72 < 0.9 x
80 < x

x > 80

x > 80

Divide both sides by -0.9, remembering to flip the inequality sign since you're dividing by a negative number:
x>80 (answer)

-.9x < -72

first divide -72 by -.9 and you get 80.

therefore x>80 because since this problem is an inequality, you flip the less than sign to a greater than sign because you divided by a negative number.