Question

Sam solved the following problem: REPOST

-4x + 5 > 29
-4x + 5 - 5 > 29 - 5
-4x > -24
-4x/-4 > -24/-4
x > 6

What were his two mistakes?

Answer 1

First mistake:

-4x > -24

Second mistake:

-4x/-4 > -24/-4

Explanation:

We are given work as

`-4x+5>29`

Step-1:

Subtract both sides by 5

`-4x+5-5>29-5`

`-4x>24`

Step-2:

`-4x>24`

Divide both sides by -4

whenever we divide by negative sign

it's inequality gets interchanged

`(-4x)/(-4)<(24)/(-4)`

`x<-6`

So, we can see that

First mistake is subtracting 5

29-5=24 ...while we have -24 there

Second mistake is to change inequality when divide by negative sign

First mistake:

-4x > -24

Second mistake:

-4x/-4 > -24/-4