Jamal and his friends are conducting a car wash to raise money for a school play. over the first weekend they raised $336.00 which was 80% of what they set out to earn. if they collect $21 for each car they wash, how many more cars must they wash?

Let's call the desired amount. We know that the 80% of x is 336. Since we compute the 80% of something by multiplying it by 0.8, we have

.

So, they still need to collect

dollars.

At a rate of 21 dollar per car, they still have to wash

cars.

add 8+12 to get a simplified answer of 12r-20

alright so i think for this one it would to draw it out. this may be hard for me to try and draw, but i will do my best on here:

        r

  /       |     \

notice how it forms 2 triangles inside one bigger triangle.

so if we know the angle spr is the same as psr that is saying the measure of angle p is the same as angle s. this means the big triangle psr is either isosceles or equilateral. in both cases, the triangle is perfectly symmetrical when split down the middle, which is in this case rq. because we know it is perfectly symmetrical on both sides, we know that the two triangles inside the bigger one are equal.