Simple calculation: 1240x8.4 + 1.24x2300 + 12.4x430

Simple calculation: 1240x8.4 + 1.24x2300 + 12.4x430

Original formula = 1240 * 8.4 + 1240 * 2.3 + 1240 * 4.3
=1240*(8.4+2.3+4.3)
=1240*15
=18600

Simple calculation formula: 1, 250 × 12 2, 306 × 24 3, 430 × 25 × 4 4, 4 × 9 × 250
5、125×3×8 6、15×4×25×6 7、65×99 8、45×(20+4) 9、99×33 10、23+56+77+144 11、246+98 12、126×8+74×8 13、25×93+25×7 14、18×25×40 15、144×37-44×37

1、250×12 =250×4×3=1000×3=30002 306×24=300×24+6×24=73443 430×25×4=430×100=430004 4×9×250=4×250×9=1000×9=90005) 125×3×8=125×8×3=1000×3=30006)15×4×25×6=15×6×(4×25)=90×100=9000...

How to use a simple method to calculate 1240 * 3.4 + 760 * 8.2 + 1.24 * 7700 + 0.76 * 2900?

1240*3.4+760*8.2+1.24*7700+0.76*2900
=124*34+124*77+76*82+76*29
=124*（34+77）+76*（82+29)
=124*101+76*101
=101*(124+76)
=101*200
=20200

White paper of the same size has 8 squares on each side (64 small squares in total). The square is cut into 4 pieces to form a rectangle. Why is it 65 small squares

You should pay attention to the angle of the triangle in the rectangle. Two angles are actually different, so there are overlaps in the rectangle. In fact, the number of squares is not equal to the area. It's incorrect to count the number of squares to determine the area at this time. You can try to cut it by yourself, and you will find that. Originally, you wanted to search for a picture on the Internet, but you didn't find it Because it's very small, it's not clear on the picture

A cylindrical wooden pile is cut along the diameter, the loading surface is a square, and the circumference of the bottom surface of the pile is 12.56 decimeters. What is the volume of the pile?

Cut along the diameter, the section is a square, then the bottom diameter = high
What is the diameter of the bottom surface
12.56 △ 3.14 = 4 (decimeter)
The volume is
(4 / 2) × (4 / 2) × 3.14 × 4 = 50.24 (cubic decimeter)

How to fill in the operation symbol of 5 () 5 () 5 = 2
What operation symbol can be used between 4 5S to equal 2? The fastest one scores! Scores!

5÷5+5÷5=2
(Olympiad Mathematics in Grade 6 of primary school)

If f (x) = ax & # 178; - ax-4 ＜ 0 holds, find the value range of real number a

If f (x) = ax & # 178; - ax-4 ＜ 0, it holds
① When a = 0, f (x) = - 4 ＜ 0 is consistent
② When a ≠ 0:
A < 0 and Δ = A & # 178; + 16A < 0
So - 16 < a < 0
In conclusion, the value range of real number a is {a | - 16 ＜ a ≤ 0}
If you don't understand, I wish you a happy study!

5x + 12x4 = 108 solution equation x-0.8x-7 = 217.6 + 3x = 10.6-x

5× 48＝108 0.2×＝28
5×＝60 ×＝140
×＝12
4×＝4
×＝1

ABCD multiplied by 9 equals DCBA. What are the a.b.c.d?
Against Satan

ABCD × 9 = DCBA, obviously a = 1, d = 9, then look at B is 0 or 1, after checking, it can only be 0, finally get C = 8, that is 1089 × 9 = 9801

(2002 · Hohhot) it is known that the images of the first-order functions y = 32x + m and y = - 12x + n pass through the point a (- 2,0) and intersect with the y-axis at B and C respectively, then the area of △ ABC is ()
A. 2B. 3C. 4D. 6

The images of y = 32x + m and y = - 12x + n all pass through point a (- 2, 0), so we can get the expressions of 0 = 32 × (- 2) + m, 0 = - 12 × (- 2) + N, ∧ M = 3, n = - 1, ∧ two functions, y = 32x + 3, y = - 12x-1, y = 32x + 3 and y = - 12x-1. The intersection points of Y axis and Y axis are B (0, 3), C (0, - 1), s △ ABC = 12bc · Ao = 12 × 4 × 2 = 4