Aphone company offers two monthly plans. plan a costs $18 plus an additional $0.10 for each minute of calls. plan b costs $22 plus an additional $0.08 for each minute of calls.

for what amount of calling do the two plans cost the same?

what is the cost when the two plans cost the same?

Step-by-step explanation:

18 + .10x = 22 + .08x

 .04x=5

x = 22/0.08 = 275 minutes, is the number of minutes the two plans cost the same

18   + .10*125 = $30.5 is the cost when the two plans cost the same  

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.