Answer to the last question of 3.3 Use the four numbers 1, 2, 3, 4 to make a row. How many four digits are there that do not repeat? How many three digits are there that do not repeat?

Tree diagram
2X3=6
Six!
Don't believe in yourself!
Me too! I have this assignment

The power of rational numbers (1)
If a rope is folded in half once, it will be broken into two pieces; if it is folded in half twice, it will be broken into 2 ＾ 2 (equal to 4), then how many pieces will be broken in half four times?

If a rope is folded in half once, it will be broken into two pieces; if it is folded in half twice, it will be broken into 2 ＾ 2 (equal to 4), then how many pieces will be broken in half four times?
Fold in half and become 2 & sup1; root at one time
Fold twice to become 2 & sup2; root
.
And so on, we have to fold 4 times, and become 2 ＾ 4 = 64

The answer to the fourth page of the seventh grade math exercise book 1

You can type out the difficult questions. I'll be able to solve them soon

If the real numbers m, N, x, y satisfy M2 + N2 = a, X2 + y2 = B, then the maximum value of MX + NY ()
A. a+b2B. abC. a2+b22D. aba+b

Let m = ACOS α, n = asin α, x = bcos β, y = bsin β, then MX + NY = abcos α cos β + absin α sin β = abcos (α - β) ≤ AB, so B is selected

4115×8.1+5.37×19+1.1×9212=______ ．

4115 × 8.1 + 5.37 × 19 + 1.1 × 9212, = 41.2 × 8.1 + 5.37 × 19 + 1.1 × 92.5, = 333.72 + 102.03 + 101.75, = 537.5, so the answer is: 537.5

The perimeter of a right triangle is 600 meters, and the ratio of three sides is 3:4:5. How many square meters is the area of this triangle?

3 + 4 + 5 = 12600 × 312 = 150 (meters), 600 × 412 = 200 (meters), 150 × 200 △ 2 = 15000 (square meters). Answer: the area of this triangle is 15000 square meters

(- 52) + (- 19) - (+ 37) - (- 24) =? - 9 + (+ 4 / 5) - (- 12) + (- 5) + (- 4 / 5) =?

(1) Original formula = - 52-16-37 + 24
=-81
(2) Original formula = - 9 + 4 / 5 + 12-5-4 / 5
=-2.

In ABC, AC = 15, BC = 13 and CD = 12, what is the area?

Because the Pythagorean theorem is satisfied (the square of a + the square of B = the square of C, the square of 12 + the square of 13 = the square of 15), the triangle is a right triangle, the right side is 12, the bottom of 13 multiplied by the height multiplied by half, and finally 78

(5x-3.2) * 4 = 19.6
There are a few more questions·
3x-2.4=9
4x/5=1.2
37-5x=11.5
All the above are solved
The following equations are listed and solved
3.2 times x minus the product of 1.4 and 7, the difference is 9.4

3x-2.4=9 4. 3.2x-1.4x7=9.4 &n...

The volume of a cone is 12dm and its bottom area is 8dm. The height of the cone is () DM

The volume of a cone is 12 DM and its bottom area is 8 DM and its height is (4.5) DM
12÷1/3÷8=4.5dm

Answer to the last question of 3.3 Use the four numbers 1, 2, 3, 4 to make a row. How many four digits are there that do not repeat? How many three digits are there that do not repeat?