The cross-section of a canal is trapezoidal, the width of the canal mouth is 3.2 meters, the width of the canal bottom is 1.6 meters, and the depth of the canal is 1.2 meters. How many square meters is the cross-section area of the canal?

(3.2 + 1.6) × 1.2 × 1 / 2 = 2.88 square meters
A: the cross section area of the canal is 2.88 square meters

The cross section of a canal is a trapezoid. The width of the canal mouth is 2.2 meters, the width of the canal bottom is 1.4 meters, and the depth of the canal is 1.3 meters. What is the cross-sectional area?

(2.2 + 1.4) × 1.3 △ 2, = 3.6 × 1.3 △ 2, = 2.34 (M2); answer: the cross section is 2.34 m2

Build a trapezoidal cross-section canal to know the width of the canal mouth is 1.8 meters, the canal bottom is 1.2 meters, and the cross-sectional area is 3 square meters. How deep is the canal excavated

Use the area of the trapezoid
Set excavation (height) y m depth
（1.8+1.2）y×1/2=3
x=2
Note that if you write without y and with X, I'm afraid to mix with X

Mathematics problem a ^ 6 = C ^ 4, B ^ 3 = D ^ 2, known a-c = 19, find C-D =?
A ^ 6 = C ^ 4, B ^ 3 = D ^ 2, known A-B = 19, find C-D =? Sorry, too tight, wrong input a letter

Let a ^ 6 = C ^ 4 = m ^ 12
,b^3=d^2=n^6,
Then a = m ^ 2, C = m ^ 3, B = n ^ 2, d = n ^ 3
It is known that A-B = 19,
So m ^ 2-N ^ 2 = 19
(m+n)(m-n)=19=1*19
M + n = 1, or M + n = 19,
m-n=19 m-n=1
The solution is m = 10, n = 9 or M = 10, n = - 9
Then C-D = m ^ 3-N ^ 3 = 1000-729 = 271 or C-D = m ^ 3-N ^ 3 = 1000 + 729 = 1729

1 / 15, 7 / 14, 5 / 15, 5 / 15, 2 / 25 ()
Twenty five of twenty-three, one of forty-five, seventeen of forty-five, seventeen of twenty-three, fifteen of forty-five ()

7/14>5/15>2/25>1/15;25/23>1>17/23>17/45>15/45

1. If the equations {ax + by = 2, {2x + 3Y = 4,
If ax by = 2 and 4x-5y = - 6 have the same solution, then a= ,b= .
2. Solve the following equations:
{ a/3+b/4=1
A / 2-B / 3 = - 1
3. If the system of quadratic equations {x + y = 2
The solution of 4x + ay / 3 = 1 is also the solution of the bivariate linear equation 3x-y = - 6
4. Known equations {a + B = 5, {a = 2, {x + Y / 2 + X-Y / 3 = 5
The solution of A-B = - 1 is b = 3. Using this result, we can solve the system of equations x + Y / 2-x-y / 3 = - 1

1、a=22/19,b=0.
2. By simplifying the original equations: {4A + 3B = 12 (1)
3a-2b=-6 (2)
(1) * 2: 8A + 6B = 24 (3)
(2) * 3: 9a-6b = - 18 (4)
(3) + (4): 17a = 6
The solution is a = 6 / 17
Substituting a = 6 / 17 into (2) gives B = 60 / 17
So the solution of the original equations is {a = 6 / 17
b=60/17
3. Because the solution of the original equation system is also the solution of 3x-y = - 6, and X + y = 2, the equation system is obtained
{3X-Y=-6
X+Y=2
The solution of the equations is: {x = - 1
Y=3
Substitute x = - 1, y = 3 into 4x + ay / 3 = 1 to get: - 4 + a = 1
Solution: a = 5
4. If the second equation is x + Y / 2 - (X-Y / 3) = - 1, you can use the above result to calculate, that is: {x + Y / 2 = 2
x-y/3=3
The solution of this system of linear equations of two variables is: {y = - 6 / 5
X=13/5
*

Please help me to find some math problems on the eighth grade
Something like that

As shown in Figure 1, in diamond ABCD, point P starts from a and moves uniformly along AB, BC and CD to the end of D at the speed of 2cm / s. point Q starts from a and P at the same time and moves uniformly along ad to the end of D. suppose the time of point P's movement is t (s). The functional relationship between the area s (cm2) and t (s) of △ Apq is shown in Figure 2

Given the square of a = a + 1, prove the 5th power of a = 5A + 3

a²=a+1
Square on both sides
a^4=a²+2a+1=(a+1)+2a+1=3a+2
Then a ^ 5 = a (3a + 2) = 3A & sup2; + 2A = 3 (a + 1) + 2A = 5A + 3

How to solve a ^ 2 + B ^ 2 + C ^ 2-ab-6b-6c + 21 = 0
Finding the value of a, B, C

The original formula is (a ^ 2-AB + B ^ 2 / 4) + (3b ^ 2 / 4-6b + 12) + (C ^ 2-6c + 9) = 0
That is, (a-b / 2) ^ 2 + 3 / 4 (B-4) ^ 2 + (C-3) ^ 2 = 0
So A-B / 2 = 0, B-4 = 0, C-3 = 0
We get a = 8, B = 4, C = 3

A square + b square + C square - ab-6b-6c + 21

(a + Half b) & sup2; + (half root sign 3 B + double root sign 3) & sup2; + (C-3) square
=a²＋b²+c²-ab-6b-6c+21

The cross-section of a canal is trapezoidal, the width of the canal mouth is 3.2 meters, the width of the canal bottom is 1.6 meters, and the depth of the canal is 1.2 meters. How many square meters is the cross-section area of the canal?