Calculate the second power of - 3, the second power of - (3 / 20), X2 / 9 = (- 1), and solve the equation x - X-2 / 5 = 2x-5 / 3-3 Hurry! / it's a fraction line First simplify and then evaluate the cubic power of 3M - 2mn-2 (the cubic power of M - the cubic power of 2mn-n), where M = - 2, n = 3

Calculate the second power of - 3, the second power of - (3 / 20), X2 / 9 = (- 1), and solve the equation x - X-2 / 5 = 2x-5 / 3-3 Hurry! / it's a fraction line First simplify and then evaluate the cubic power of 3M - 2mn-2 (the cubic power of M - the cubic power of 2mn-n), where M = - 2, n = 3

Calculate the second power of - 3, the second power of - (3 / 20), the second power of x2 / 9 - (- 1), the power of 2012 = - 9-9 / 400 × 2 / 9-1 = - 9-1 / 200-1 = - 10 and 1 / 200, solve the equation x - (X-2) / 5 = (2x-5) / 3-3, remove the denominator 15x-3 (X-2) = 5 (2x-5) - 45, remove the bracket 15x-3x + 6 = 10x-25-45, merge the similar term 2x = - 76, and change the coefficient to 1 to get x = - 38

Solving the fractional equation (1) 2x + 1-xx2-1 = 0 (2) 1x-3-23-x = 12x2-9

(1) By multiplying (x-1) (x + 1) on both sides of the equation, we can get 2 (x-1) - x = 0 and sort out the solution to get x = 2. By testing, x = 2 is the solution of the original equation. (2) by multiplying (x-3) (x + 3) on both sides of the equation, we can get 3 (x + 3) = 12 and sort out the solution to get x = 1. By testing, x = 1 is the solution of the original equation

Solving fractional equation: 1 / (x2-x) = 2 / (x2-2x + 1)

1/(x2-x)=2/(x2-2x+1)
Can be converted into
1/x(x-1)=2/(x-1)(x-1)
We can see that x ≠ 1 and X ≠ 0
Multiply both sides by X (x-1) (x-1)
So (x-1) = 2x
So x = - 1

Woodworking to do a pair of 50 cm long, 40 cm wide, 12 cm deep cuboid drawer, at least to use wood how many square decimeters

A: at least 48 square decimeters of wood should be used

How many square centimeters of wood should be used to make a drawer 50 cm long, 40 cm wide and 12 cm deep?

50 × 40 + 50 × 12 × 2 + 40 × 12 × 2 = 2000 + 1200 + 960 = 4160 (square centimeter) a: at least 4160 square centimeter of wood should be used

A drawer is 50 cm long, 30 cm wide and 10 cm high. How many boards do you need to make such two drawers?

Hello;
（50×30+50×10×2+30×10×2）×2
=（1500+1000+600）×2
=6200 (square centimeter)

The circumference of semicircular paperboard is 10.28 decimeters, how much is the area (to process) please thank you

Let the radius of the paper be r, then its perimeter is 2R + pi * r = 2R + 3.14r = 5.14r = 10.28 (decimeter) to get r = 2 (decimeter), so its area is (pi * R ^ 2) / 2 = 6.28 (square decimeter)

Use a piece of rectangular cardboard with a circumference of 12.56 cm and a width of 9.42 cm to form a cylinder. How to make a large volume? How much is it?

Use a piece of rectangular cardboard with a length of 12.56 cm and a width of 9.42 cm to form a cylinder. How to make a large volume? How much is it?
56 cm, the largest volume
Radius 12.56 △ 3.14 △ 2 = 2cm
Volume 3.14 × 2 × 2 × 9.42 = 118.3152 cm3

A ring, the circumference of the outer circle is 12.56 decimeters, the diameter of the inner circle is 3 decimeters, how many square decimeters is the area

Outer circle diameter = 12.56 △ 3.14 = 4
Area = 3.14 * (4 △ 2) square -- 3.14 * (3 △ 2) square = 5.495 square decimeters

There are three numbers a, B and C, the sum of a and B is 91, the sum of a and C is 83, and the sum of B and C is 66
emergency

Explanation
Because a + B = 91
A+C=83
B+C=66
2(A+B+C)=91+83+66
A+B+C=240÷2
A+B+C=120
The average is 120 △ 3 = 40