Me! : ^) i need with #8. it says: a farmer owns a triangular field with a perimeter of 9a + 4b - 5. which of the following could be side lengths of the field? a: 3,-2+2b,2b+9a b: 3a,3a+5, and 4b c: 8a,1a+3b, and b-5 d: 9,4b, and -5a

It's number C, because if you get the sum of the expressions you get the perimeter of 9a + 4b - 5.

2160ft3

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.