How many 7-digit phone numbers can be formed if the first digit cannot be 0 or 1, and any digit can be repeated

8 × 10⁶

Step-by-step explanation:

The first digit can be any number from 2 to 9. We can select any of the eight digits.

We can select the remaining digits in ten different ways.

Each choice is independent, so we can multiply the choices together.

N = 8 × 10 × 10 × 10 × 10 × 10 × 10

  = 8 × 10⁶ possibilities

There are 8 × 10⁶ possible seven-digit phone numbers.

none.

step-by-step explanation:

m

1

=

5

m1=5

b

=

−

1

b=-1

find the slope and y-intercept of the second equation.

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m

2

=

0

m2=0

b

=

−

6

b=-6

compare the slopes

m

m of the two equations.

m

1

=

5

,

m

2

=

0

m1=5,m2=0

compare the two slopes in the decimal form. if the slopes are equal, then the lines are parallel. if the slopes are not equal, then the lines are not parallel.

m

1

=

5

,

m

2

=

0

m1=5,m2=0

step-by-step explanation: