From a point on a river, two boats are driven in opposite directions, one at 7 miles per hour and the other at 11 miles per hour. In how many hours will they be 54 miles apart?

Both boats will be 54 miles apart after 3 hours.

Step-by-step explanation:

Given that from a point on a river, two boats are driven in opposite directions, one at 7 miles per hour and the other at 11 miles per hour, to determine how many hours they will be 54 miles apart, the following calculation must be performed :

54 / (11 + 7) = X

54/18 = X

3 = X

Therefore, both boats will be 54 miles apart after 3 hours.

-14

step-by-step explanation:

2x2 – 2(x+4)

=2x2-2（5+4）

=4-2×9

=4-18

=-14

geometric series converge the common ratio r has magnitude less than one.

which is equivalent to

for the example we need

|2-x| < 1

-1 < 2-x   and 2-x < 1

x < 3 and x > 1

we can write that

answer: 1 < x < 3

1a. common ratio r=250/25=10 > 1     diverges

1b.   r=50/100=1/2 converges

when these converge they converge to

where a is the first term.

answer: 200

1c. r=-1   so it's not the case that |r| < 1.     diverges

2a. x is the common ratio so we converge when |x|< 1

2b.   r=-10x / -2 = 5x.

we converge when

|5x| < 1

|x| < 1/5

2c.   r=3-2x

-1 < 3-2x and 3-2x < 1

-4 < -2x and 2 < 2x

x < 2 and 1 < x

1 < x < 2

2d. [/tex] r=-48x^3/12 = 4x^3[/tex]

|4x^3| < 1

|x^3| < \frac 1 4

|x| < 4^{-1/3}