How do you solve 4 > -3x + 3 or 8 ≤ -2x + 5?

↳Redirected from "A 5.00 L sample of helium at STP expands to 15.0 L. What is the new pressure on the gas?"
1 Answer
Olivier B.
Jun 28, 2015

#4> -3x+3 rarr x> -1/3#

#8<=-2x+5 rarr x<=-3/2#

Explanation:

Solving an inequation is the same as solving an equation, except that the orientation of the inequality will change when you multiply or divide by a negative number.

Let's start with #4> -3x+3#

#rarr 4-3> -3x+cancel(3)-cancel(3)#
#rarr 1/3 > -(cancel(3)x)/cancel(3)#
#rarr -1/3 < -(-x) rarr x> -1/3#

Now #8<=-2x+5#

#rarr 8-5<=-2x+cancel(5)-cancel(5)#
#rarr 3/2<=-(cancel(2)x)/cancel(2)#
#rarr -3/2>=-(-x) rarr x <= -3/2#

Related questions
See all questions in Compound Inequalities
Impact of this question
2529 views around the world
You can reuse this answer
Creative Commons License