Amanda and Alexis live 4 miles apart. They decide to start walking toward each other’s houses at the same time. Amanda walks at a rate of 3.5 miles per hour and Alexis walks at a rate of 4 miles per hour. How long will it take for them to meet? Round to the nearest hundredth of an hour. [Remember: D = (r)(t)] Two boxes, one with Amanda and 3.5 m p h. To the right is the other box with Alexis and 4 m p h. Below, the boxes there is a bracket, halfway between, pointing to 4 miles.
hour

t = 0.53 hr

Step-by-step explanation:

We write expressions for the distances walked by these two people, sum them up and set the sum equal to 4 miles:

(3.5 mph)(t) + (4mph)(t) = 4 mi

Combining these terms:  

(7.5 mph)(t) = 4 mi

                               4 mi

Solving for t:  t = = 0.53 hr

                              7.5 mph                              

chase is right because he already been to the swings and he know how far it will be to get there

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.