The perimeter of a basketball court is 72m. The difference between its length and its width is 12m. Solve the system to determine the dimensions of the court. I keep getting different answerers and can't seem to find the right on. Please help.

• It would be easier to help if you showed your attempts -- then people could try to figure out which wrong things you need to unlearn instead of just showing you the right solution (which you have probably already seen in class for other similar problems, and it hasn't helped you stop doing wrong things in your own attempts). – hmakholm left over Monica Mar 15 '16 at 16:34

Let the length be $l$ metres and breadth be $b$ metres.

$2(l+b) = 72$ and $l = b + 12$ These two are the main linear equations.

So, $$2(b+12+b) = 72 \implies 4b + 24 = 72$$ $$4b = 48 \implies b = 12 \implies l = 20$$

So, length and breadth are 20m and 12m respectively.

Your question give us the information we need to make two equations.

First: $2l + 2w = 72$. This shows that the perimeter is 72 m.

Second: $l - w = 12$. This shows that the difference between its length and width is 12m.

Now we have to solve these equations. We can rearrange (2) to get $l = 12 + w$. We then substitute that into (1) and get $2(12 + w) + 2w = 72$. We can simplify that to get $24 + 4w = 72$. If we solve for $w$ we get $w = 12$. Now we need to find $l$. Just put $w$ into $l = 12 + w$ and we get $l = 24$.

$2l + 2w=72\\l-w=12$
Now, just solve the second equation for either $l$ or $w$ and plug that into the first equation, then after some more algebraic manipulation you should be able to solve the system