Xiao Gang knows that he is wrong and he is in a heavy mood. How to correct this sentence?

Xiao Gang knows that he is wrong and he is in a heavy mood. How to correct this sentence?

Xiao Gang knew that he was wrong, and his heart was heavy

Xiaogang and Xiaojun make an appointment to visit his home on Sunday

Replace "he" with a specific person (Xiao Gang or Xiao Jun)

This semester, Xiao Gang understood and corrected his learning attitude

Learning attitude can't be understood. It's improper collocation of word meaning, so it should be changed to
This semester, Xiao Gang corrected his attitude towards study

7(x+6)-3x=(2x+5)
7(x+6)-3x=4(2x+5)
It seems that a 4 is missing

7(x+6)-3x=4(2x+5)
7x+6*7-3x=8x+4*5
7x+42-3x=8x+20
7x-3x-8x=20-42
(7-3-8)x=-22
-4x=-22
x=5.5

Two squares of equal size form a rectangle. The perimeter of the rectangle is 48CM. How about the perimeter and area of the original square?

If the side length of the square is a, the perimeter of the new rectangle is 6 * a
So the square side length is 48 / 6 = 8cm
The perimeter is 4 * 8 = 32cm
The area is 8 * 8 = 64cm ^ 2

What is 1 Rev / min equal to rad / s in physics

1 rev = 2π rad
1rev/min= 2π rad /60 s= π/30 rad/s

The solution equation: X & sup2; + 3x-16 + 12 / x = 0
I haven't learned the root formula three times

x^3+3x^2-16x+12=0
x^3+3x^2-4x-12x+12=0
x(x^2+3x-4)-12(x-1)=0
x(x-1)(x+4)-12(x-1)=0
(x-1)(x^2+4x-12)=0
(x-1)(x-2)(x+6)=0
x=1,2,-6

Three equal size squares, put together into a rectangle, the circumference of this rectangle is 24 cm, the side length of each square is 24 cm______ Centimeter. What's the area of this rectangle______ Square centimeter

24 △ 8 = 3 (CM), 3 × 3 × 3 = 27 (cm 2)

On the velocity formula of uniform linear motion v = s / T, it is judged that the velocity does not change with the change of time and distance
What I think is that if the time distance changes from 1 s 30m to 2 s 80m

It must be right, because it is moving in a straight line at a constant speed, so the speed does not change with time and distance

Simplification: (1) 2 | x | - 3x / | - 2x - | - 5x | (2) | - x + 5 | + | - 2x-3 | (3) | - 3 + | - 2 - | - 1 + X|||

(1) When x > = 0, the original formula is 2x-1
When x