I believe it might be 4:2 based on how you asked it.
Answer:
Phone 1 will allow Ellie to talk the longest
Step-by-step explanation:
Phone 1:
(0.10x) + 6 = y
(0.10x) + 6 - 6 = 22 - 6
0.10/0.10x = 16/0.10
x = <u>160</u> minutes
Phone 2:
(0.25x) + 5 = y
(0.25x) + 5 - 5 = 22 - 5
0.25/0.25x = 17/0.25
x = <u>68</u> minutes
The answer is 4*\sqrt(2), or 5.7 if rounded to the nearest tenth digit. Notice that this is a right triangle (F is the right angle). The length of FG and FE are both 4 units on the diagram. Therefore, according to the Pythagorean theorem, the length of EG is \sqrt(4^2+4^2)=4*\sqrt(2), which is about 5.7.
Multiply 7 by 9 and you will get 63 which is x.
Below 5 → round down
5 and up → round up
Look at the number in ones' place: 9
Round up the number in tens' place to 5
Look at the number in tens' place: 5
Round up the hundreds' place to 7
Result : 4278700