How do you solve the inequality #9 - x > 10#?

2 Answers
Dec 27, 2015

Answer:

#x < -1#

Explanation:

You first substract 9 at both sides. So #9 - x > 10 iff -x > 1#. You then multiply both sides by #-1# in order to have the inequality for #x#. Be careful, opposites and quotients change the direction of an inequality!

So #-x > 1 iff (-1)*(-x) < -1 iff x < 1#

Dec 27, 2015

Answer:

Isolate x to solve the inequality

Explanation:

9 - x > 10
-x > 1
x < -1 *

*Always flip the inequality sign's direction when dividing the constant term on one side by a negative coefficient of x.

The answer is x < -1

Have a good day!