Khan/khan-exercises — Issue #4493: Compound inequalities - Compound inequalities wrong answer listed
Author: KhanBugz
Created: 2011-10-17 19:04:18+00:00
State: open
Labels: safari, snowleo

Reporter: jonesman107@gmail.com

this is wrong? shouldn't it be z>3?

9z+8≥62 and 6z+4>22
The first inequality can be simplified into this:

z≥6
The second inequality can be simplified into this:

z>3
−2−1012345678
The solution to an inequality with the word "and" is the intersection of the graphs of the inequalities.

Since the first inequality is completely included by the second inequality, their intersection is the first inequality. Therefore the answer is:

z≥6

[compound_inequalities.html?seed=196&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/compound_inequalities.html?seed=196&problem=0&debug)

["z≥6 and z>3"]

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