A few 6th grade math calculation questions, urgent! Look at the homework and point to the maze

1)-2x-7=9-10x

Solution: -2x+10x=9+7

8x=16x=2

2) Solution: x=25 9

3) 3-8 (x-5/2) = 3x

Solution: 3-8(x 4-5 2)=3x

3-2x+20=3x

23=5xx=23/5

4) 6 (2-1/3 y) - 1/5 (10-15y0=1 after Oh 0 is this -)

Solution: 6(2-y 3)-1 5(10-15y=112-2y-2+3y=1

What the hell is this 0 of yours? I don't understand....

5) 3/3 - x-2/2 x-2 = 1

Solution: 3 3-x-x 2-2=1

1-x-x/2-2=1

3x/2=2

3x=4x=4/3

6) x+1 of 2 = 15x-17 of 4

Solution: x 2+1=15x 4-17

x/2-15x/4=-17-1

13x/4=-18

13x=18*4

x=72/13

7) -2 of 3 + (-5 out of 6) - (1 out of 9) - 6 points 1 solution: -2 3-5 6 + 1 9-1 6

8) [(1/6-1/21)*42] 3 square solution: [1 6-1 21)*42]*9

Children learn to do it themselves, there are not many people I understand it on the Internet, and it is too easy to do this problem with your Internet strength.

1.An increase in height of 2cm increases the surface area, but in fact, the increase in the surface area is the increase in the side area, so dividing by 2 is the side length of the original side area. So it turns out that the side area of this cylinder is multiplied, and the final result is calculated by yourself!

2.The reduction in surface area is due to the fact that the rectangular sides of the two semi-cylinders are hidden, so the rectangular side area of the semi-cylinder is 1 square centimeter. The radius of the base surface of the cylinder is 3 cm, and the diameter is 6 cm, so the length of the other side of the rectangle = 1 square centimeter 6 cm = 1 6 cm, which is the height of the cylinder.

The circumference of the bottom surface of the cylinder = 2 r = 2 times 3, so the side area of the cylinder = 1 6 times 2 r

3.The radius of the base surface is 1 decimeter, and the area of a base surface = the square of r multiplied by . So the side area is the area of the two bottom surfaces. According to the radius, we can know the perimeter of the bottom surface, that is, the length of one side of the side, and divide the side area by the side length of this side to the height of the cylinder.

4.The height is reduced by 2cm, and the area reduced is the area of the side that is reduced, and the square centimeter is 2cm, which is the circumference of the bottom surface of the cylinder, which is centimeters. Multiply by 10 = square centimeters, which is the side area of the original cylinder.

Let's find the bottom area, the circumference of the bottom surface, so use the radius of the bottom surface, and know the bottom area of the radius. The area of the two bottom surfaces + side area is the area of the original cylinder.

1.(divide by 2).

2.The height of the cylinder is: 1 divided by (2 times 3), and this height is multiplied by the circumference of the circle: 2 times multiplied by 3

3.The height of the cylinder = (surface area - circle area multiplied by 2) divided by the base circumference.

Dizzy.. Study hard.,It's always good to read books by yourself.。。。

1;This is the circumference of the bottom surface of the cylinder, and it is also the length of the sides of the square" Note: * is multiplication.

It's better to do it yourself and don't let your head rust.