Sandra saves 12% of her salary for retirement. This year her was $3,000 more than in the previous year, and she saved $4.20. What was her salary in the previous year?

2 Answers
Jul 21, 2018

First, we want to figure out what her salary was this year. We know that #$4.20# is #12%# of her salary and we can show it with:

#12%*x=$4.20#, where #x# represents this year's salary

Solve for #x#
#.12x=$4.20#

#x=$35#, which is her salary for this year, and we just have to subtract the #$3,000#

With this, we know that you stated the problem incorrectly, but this method of solving can still be used with any similar problem.

Jul 21, 2018

See below

Explanation:

Let's say that was in fact #4.20# dollars, and this year her salary was #3000# dollars more than her last year's salary:

Let #x# be last year's salary

Let #x+3000# be this year's salary:

So:
#0.12(x+3000)= 4.20#

#0.12x+360= 4.20#

#0.12x= -355.8#

#x=-2965# dollars

Last year she didn't earn anything and spent 2965 dollars :)