If the edge length of a cube is a, then the surface area and volume of the cube are,

If the edge length of a cube is a, then the surface area and volume of the cube are,

6a²
a³

How many meters is a rectangle 3 / 4 m wide and 1 / 3 m long

A rectangle is 3 / 4 m in width, 1 / 3 m in width, and its circumference is 2 * (3 / 4 + 1 / 3) = 13 / 6 m, that is 13 / 6 m

A 3 m long and 1 m wide rectangular blackboard is surrounded by a 7.5 cm wide frame. Is the frame similar to the blackboard
It's a rectangle one and a half meters wide

It's not similar
Side length ratio of inner rectangular blackboard = 3 / 1.5 = 2 (in meters)
Side length ratio of rectangle outside border = (300 + 2x7.5) / (150 + 2x7.5) = 315 / 165 ≠ 2 (in cm)
It can be seen that their side length ratio is not equal, so the border is not similar to the blackboard

3 / 5 × fractions = 7 / 6 × fractions judgment: given 1 △ a = B, then a is the reciprocal of B ()

3/5×7/6=7/6×3/5
correct

For a piece of iron wire, half of it is less than 1m when used for the first time, and the remaining half is more than 1m when used for the second time. As a result, there is still 2.5m left. How long is this iron wire?
Let X be 0.5x + 1 - (0.5x + 1) * 0.5-1 = 2.5
X=12

0.5x+1-0.5（0.5x+1）-1＝2.5
0.5x+1-0.25x-0.5-1＝2.5
0.25x＝3
x＝12
A: the wire is 12 meters long. You are right
Good luck and goodbye

For a piece of iron wire, more than half of its total length is used for the first time, and less than 1m is used for the second time. The remaining half is 3.5m. How many meters is the original length of iron wire
For a piece of iron wire, one half of the total length is more than 1m for the first time, the remaining half is less than 1m for the second time, and there is still 3.5m left. How many meters is the original length of iron wire

My mother used a piece of iron wire to make a clothesline. For the first time, she used more than half of his clothesline by 1m. For the second time, she used the remaining half by 1m. At this time, there was still 3.5m left,
How long is the wire?

Let the original length of the wire be X. according to the meaning of the title: (x / 2-1) / 2 + 1 = 3.5, x = 12 (m), so the original length of the wire is 12 meters

There is a meter long iron wire. For the first time, half of it is less than 1m, and for the second time, half of it is more than 1m. How many meters is left?

a-(a/2-1)-[(a/2+1)×1/2+1]
=a-a/2+1-a/4-1/2-1
=a/4-1/2
There are (A / 4-1 / 2) meters left on this wire

There is a piece of iron wire with the length of am. The first time, half of it is less than 1 meter, and the second time, half of it is more than 1 meter. How many meters is left

First use: A / 2 - 1
The second use: [a - (A / 2 - 1)] / 2 + 1 = A / 4 + 3 / 2
Surplus: a - (A / 2-1) - (A / 4 + 3 / 2) = (A / 4 - 1 / 2) M

For one wire, half of it was less than 1m in the first time, and half of the remaining wire was more than 1m in the second time. As a result, the remaining wire was 2.5m,
How long is the wire?

12 m