We can write two equations for this. x = each minute of calls

Plan A = .1x + 16
Plan B = .14x

Make the two equations equal each other, so we can find when they are the same.

.1x + 16 = .14x

Subtract .1x from both sides

16 = 0.04x

Divide by 0.04 to get x by itself

400 = x.

Earlier, we set x as each minute of calls. This means that after 400 calls, Plan A and Plan B will cost the same.

To find the cost, substitute 400 into both equations by themselves.

Plan A cost = .1x + 16
Plan A cost = .1(400) + 16
Plan A cost = 40 + 16
Plan A cost = $56

Plan B cost = .14x
Plan B cost = .14(400)
Plan B cost = $56

Final answer: After 400 calls, Plan A and Plan B will both cost $56.

8 0

2 years ago

A 90-inch length of ribbon is to be cut into three pieces. The longest piece is to be 30 inches longer than the shortest piece,

Free_Kalibri [48]

Lets name the shortest piece a, the medium b and the longest c

Together they are 90inches
$a + b + c = 90$
The longest is 30 inches longer than the shortest
$c = a + 30$
The third piece is half the lenght of the longest
$b = \frac{c}{2}$

So if you place c=a+30 in the other 2 equasions you get

$a + b + (a + 30) = 90 = 2a + b + 30$
And
$b = \frac{30 + a}{2}$
Now if you put this 2 toghether u get
$2a + \frac{30 + a}{2} + 30 = 90$
Multyplied by 2
$4a + 30 + a + 60 = 180$
$5a = 90$
Meaning that a=18inches

Now that we have the lenght of a we put it in the previous equasion

$b = \frac{30 + 18}{2}$
So b=48/2 which means b=24inches

And together they must be 90 so

$18 + 24 + c = 90$

C=48inches

6 0

3 years ago