Calculate 2 / 5 + 3 / 4 + 2 / 3 = 2 / 3 - (1 / 4 + 1 / 5) = 25 / 28 - (3 / 7 + 5 / 14)=

Calculate 2 / 5 + 3 / 4 + 2 / 3 = 2 / 3 - (1 / 4 + 1 / 5) = 25 / 28 - (3 / 7 + 5 / 14)=

2 / 5 + 3 / 4 + 2 / 3 = 24 / 60 + 45 / 60 + 40 / 60 = 89 / 60 = 1 and 29 / 60
2/3-（1/4+1/5）=40/60-15/60-12/60 =13/60
25/28-（3/7+5/14）= 25/28-12/28-10/28=3/28

Skillfully calculate 1 / 1 * 4 + 1 / 4 * 7 + 1 / 7 * 10 +. 1 / 25 * 28

The original test = 1 / 3 * (1-1 / 4 + 1 / 4-1 / 7 +. + 1 / 25-1 / 28) = 9 / 28

What's 42:28?

42:28 Du △ 14
=3：2
=3 / 2
That is 1.5

You can find the 55th power of (- 2) + (- 2) 49th power + (- 2) 48th power + ···· + (- 2) + 1

This is the sum of the first 50 items of the equal ratio sequence with the first term of 1 and the common ratio of - 2
Sn=1*[1-(-2)^51]/[1-(-2)]=(2^51+1)/3
If you just do as you said above, first calculate the sum of the last 50 items
S=1*[1-(-2)^50]/[1-(-2)]=(-2^50+1)/3
The final result is: - 2 ^ 55 + (1-2 ^ 50) / 3

When can four minus three equal five?

1. When the calculation is wrong 2. Cut off a triangle from the four corners, and it will be a Pentagon

Under what circumstances is 4 minus 3 equal to 5?

The answer: a square minus a triangle equals a Pentagon

When will four minus three equal five

A square minus a triangle

Under what circumstances (non Mathematics): 4 minus 3 equals 3? 4 minus 3 equals 4? 4 minus 3 equals 5?

A square cuts a corner, and the remaining figure has several corners
The answer is 3 4 5

Under what circumstances is 4-3 equal to 5
When can 4-3 be equal to 5 if the calculation is absolutely not wrong?

Quadrilateral cut off a three triangle, equal to the Pentagon

Under what circumstances do 4 minus 3 wait for 5

In case of miscalculation