The youth soccer team is fundraising by washing cars. They paid $84.55 for supplies. If they charge $8.00 per wash, how many cars must be washed to profit at least $300.00 dollars?

The soccer team must wash 49 cars in order to gain at least $300.

Step-by-step explanation:

The soccer team started out by paying $84.55.  They charge $8 per car wash.  So let's say how many cars they washed was x.  They need to gain at least $300 dollars.  If we put this in an equation it looks like this (we are solving for x):

8x - 84.55 >or= 300

To find x we have to do the following steps:

8x - 84.55 >= 300

    + 84.55     + 84.55

8x >= 384.55

/8          /8

x >= 48

Now we have to make sure that this is correct:

8 * 48 - 84.55 = ?

384 - 84.55 = 299.45

Since 299.45 is less than 300, x must be greater than 48, but since 299.45 is so close to 300, my educated guess would be that x=49.  

8 * 49 - 84.55 = ?

392 - 84.55 = 307.45

Since 307.45 is greater than 300, x=49.  So we can conclude that they must wash 49 cars to profit at least $300.

a) what number, when added to negative four, is equal to negative five?

step-by-step explanation:

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.