Tom purchased international calling cards before traveling abroad. He bought a 60-minute card for $9.99, a 90-minute card for $14.29, a 100-minute card for $17.99, and a 200-minute card for $29.49. After using all of his calling cards, Tom used his mobile phone for 38 minutes at a rate of $2.99/minute.

20

step-by-step explanation:

step-by-step explanation:

first, eliminate the parenthesis:

3

x

+

2

−

4

x

second, group like terms:

3

x

−

4

x

+

2

third, combine like terms:

(

3

−

4

)

x

+

2

→

−

1

x

+

2

→

−

x

+

2

the number 100 represents the number of trials in the experiment.

49/100 represents the experimental probability of the coin landing heads up.

step-by-step explanation:

180°

step-by-step explanation:

sum of equilateral triangle=180°

< n=60°

< m=120°°[angle supplementary of equilateral angle]

< m+< r+< x=360°(sum of exterior angle of triangle)