help please

[8dltndus]

I don't get this at all... i am stuck on this section(lesson)
and the question goes like this...

The differnce between the length and the width of a rectangle is 2 units. The perimeter is 40 units.
Write and solve a system of equations to determiine the length and the width of the rectangel.(hint: The perimeter of a rectangle is 2l+2w)



So! what I did was...nothing...*sigh*
does it go like this? the first equation?:2l+2w=40

help D:

 

[wjm11]

I don't get this at all... i am stuck on this section(lesson)
and the question goes like this...

The differnce between the length and the width of a rectangle is 2 units. The perimeter is 40 units.
Write and solve a system of equations to determiine the length and the width of the rectangel.(hint: The perimeter of a rectangle is 2l+2w)



So! what I did was...nothing...*sigh*
does it go like this? the first equation?:2l+2w=40

help D:

2l+2w=40 is a good start.

Next, let's talk about how we convert a sentence into math. What do you suppose "difference" or "difference between" might mean? It means that if you SUBTRACT one value from another, you can find the difference in their values, right? So... "The difference between the length and the width" simply means: l - w. And we're told that the difference is 2 units. Therefore:

l - w = 2

you now have two equations and two unknowns (l and w), so you can solve.