If the length of a rectangle is increased by 30% and the width of the same rectangle is decreased by 30%, what is the effect on the area of the rectangle?

The answer is: It is decreased by 9%
But I have no clue how to do this problem.

Question

If the length of a rectangle is increased by 30% and the width of the same rectangle is decreased by 30%, what is the effect on the area of the rectangle?

The answer is: It is decreased by 9%
But I have no clue how to do this problem.

caozeyuan · Answer

A=w*d, right?

caozeyuan · Answer

So, x%*A=1.3d* .7w, solve the equation and you have 91%, so it is 9% less

gabyramirezzz · Answer

I think so? I'm not sure at all really

caozeyuan · Answer

KNOW YOUR FOMULA!!!

caozeyuan · Answer

if they don't provide equation sheet on exams

gabyramirezzz · Answer

It's for the SAT

caozeyuan · Answer

Well,, know how to solve equation then

caozeyuan · Answer

Wait? you are high school and you still freak out on this type of questions?! I mean, yes, we chinese are best on math, but this type of question is just too easy to get it wrong

gabyramirezzz · Answer

thanks for your help...