The area of a trapezoid is 50 square decimeters, the sum of its top and bottom is 16 meters, and its height is 10 meters______ ．

The area of a trapezoid is 50 square decimeters, the sum of its top and bottom is 16 meters, and its height is 10 meters______ ．

16 meters = 160 decimeters, 50 × 2 △ 160 = 0.625 (decimeters), so the answer is: 0.625 decimeters

It is known that the height of the trapezoid is 7 cm and the area is 56 square cm. Its upper and lower bottoms are more than 1 / 3 and more than 4 cm. How many are the upper and lower bottoms of the trapezoid
Use binary once

If the lower base is x cm, then the upper base is x / 3 + 4 cm
（x+x/3+4）×7÷2=56
x+x/3+4=16
4x/3=12
x=9
x/3+4=7
A: the upper sole is 9cm and the lower sole is 7cm

Known blank area is 12.56 square centimeter, calculate shadow area

12.56 × 4 △ 3.14, = 50.24 △ 3.14, = 16, and because 4 × 4 = 16, the radius of the circle is 4cm; therefore, the area of the shadow part is: (4 + 6) × 4 △ 2-12.56, = 10 × 4 △ 2-12.56, = 20-12.56, = 7.44 (square centimeter); a: the area of the shadow part is 7.44 square centimeter

Comparative size: 1; 4000 square centimeter 2; 56 square decimeter 3; 3 square meter 4; 1 square meter 2 square decimeter 5; 310 square decimeter

4000 sq cm = 0.4 sq m
56 square decimeter = 0.56 square meter
3 square meters
1 square meter 2 square decimeter = 1.02 square meter
310 square decimeters = 3.1 square meters
310 square decimeters ＞ 3 square meters ＞ 1 square meter ＞ 2 square decimeters ＞ 56 square decimeters ＞ 4000 square centimeters

A pair of leather shoes to cowhide 8.1 square decimeters, a 56 square decimeters of cowhide can do how many pairs of shoes?

I think it should be six pairs. If it's seven pairs, it needs 56.7 square decimeters of cowhide

Given (A's square + B's Square) (A's square + B's Square-1) = 56, find the value of a's square + B's Square

Let x = the square of a + the square of B
x(x-1)=56
x²-x-56=0
(x+7)(x-8)=0
Because the square of a + the square of B ≥ 0
So the square of a + the square of B = x = 8

(x-1) 2 = (x + 1) + 56 2 is the square,

（x-1）2=（x+1）+56
（x-1）^2-(x-1-)-56=0
(x-1-8)(x-1+7)=0
(x-9)(x+6)=0
X = 9 or x = - 6

A piece of land 56 mu, 1 mu is equal to how many square meters

An acre is about 667 square meters. The decimal place is the cycle of 6

3 / 2 + 13 / 6 + 37 / 12 + 81 / 20 + 151 / 30 + 253 / 42 + 393 / 56 + 577 / 72 + 730 / 81 + 1101 / 110

3/2+13/6+37/12+81/20+151/30+253/42+393/56+577/72+730/81+1101/110
=1+1/2+2+1/6+3+1/12+4+1/20+5+1/30+6+1/42+7+1/56+8+1/72+9+1/81+10+1/110
=（1+2+3+4+5+6+7+8+9+10）+（1/2+1/6+...+1/110）
=55+（1/1×2+1/2×3+1/3×4+1/4×5+1/5×6+1/6×7+1/7×8+1/8×9+1/9×10+1/10×11）
=55+（1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10+1/10-1/11）
=55+1-1/11=55+10/11=615/11.

3 + 13 / 6 + 37 / 12 + 81 / 20 + 151 / 30 + 253 / 42 + 393 / 56 + 577 / 72 + 811 / 90?

3+13/6+37/12+81/20+151/30+253/42+393/56+577/72+811/90=3+2+1/6+3+1/12+4+1/20+5+1/30+6+1/42+7+1/56+8+1/72+9+1/90=3+2+3+4+5+6+7+8+9+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90=3+(2+9)*8/2+1/2*3+1/3*4+1/4*5+1/...