How do you solve #m/2-7>4#?

2 Answers
Feb 28, 2016

Answer:

#m>22#

Explanation:

#m/2-7>4#

Add 7 to both sides.

#m/2>4+7#

Simplify.

#m/2>11#

Multiply both sides by 2.

#m>11xx2#

Simplify.

#m>22#

Feb 28, 2016

Answer:

#m>22#

Explanation:

Given:#" "m/2-7>4#

You treat this like a normal equation. There is one 'trap' however. If the whole thing is multiplied by a negative number the inequality is turned round the other way.

For example: It is true that #2<4#

Now consider the incorrect calculation of:

#(-1)xx2<(-1)xx4 " implying that " -2<-4# which is false

#-2# is to the right of #-4# on the number line so #-2 > -4#

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Add 7 to both sides giving

#m/2-7+7 >4+7#

#m/2+0>11#

Multiply both sides by 2 giving

#2/2xxm>2xx11#

But #2/2 =1# giving:

#m>22#

'~~~~~~~~~~~~~~~~~~~~~~~~~