Kelsey says that to solve the equation 3x + 6 = 24, the first step should be to subtract 6 from each side of the equation. Dana says the first step should be to divide each term by 3. Decide and explain if Kelsey or Dana is doing the first step correctly.

Kelsey is correct.

Step-by-step explanation:

One of the rules when solving an equation is that you need to isolate the variable, meaning that it just needs to be x by itself. To do that, you would need to start by subtracting 6. If you were to divide by 3 first, the answer would be twice what it should be.

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.