Known trapezoid area is 36 square meters, the bottom is 3 meters, the bottom is 5 meters, how high is it?

Known trapezoid area is 36 square meters, the bottom is 3 meters, the bottom is 5 meters, how high is it?

S trapezoid: (a + b) × h △ 2
（3+5）×h÷2=36
h=9

It is known that the area of trapezoid is 42 cm 2, the height is 6 cm, and its bottom is 1 cm less than 2 times of the top

According to the meaning of the question, we get y = 2x − 112 (x + y) × 6 = 42, and the solution is x = 5Y = 9. A: the upper bottom of the trapezoid is 5cm, and the lower bottom is 9cm

A town plans to build a channel with isosceles trapezoid section, with a section area of 1.53 square meters. The width of the upper opening is 1.4 meters wider than the lower width of the channel, and the depth of the channel is 0.1 meters less than the width of the channel bottom

Upper opening width = 1 + 1.4 = 2.4m
Channel depth = 1-0.1 = 0.9m

(a + B-1) (a-b + 1) = () and#178; () and#178; process of finding,

(a + B-1) (a-b + 1) = (a + (B-1)) (a - (B-1)) = (a) square - (B-1) square
Let's share the same bed

(a + 1) &# 178; + √ (7 + b) = 0, then a + B=

—8

To prove: A & # 178; + B & # 178; - 1-A & # 178; B & # 178; ≤ 0, just prove

To prove: A & # 178; + B & # 178; - 1-A & # 178; B & # 178; ≤ 0, just prove
(a² -1)(b²-1)≥0
The results show that a & # 178; ≥ 1, B & # 178; ≥ 1 or 0 ≤ A & # 178; ≤ 1, 0 ≤ B & # 178; ≤ 1

If - B = 5,1 / a = a, then 3 × A & # 178; - (B + a) &# 178; =?
A - 33 B - 13 C 33 D - 13 or - 33

If B = - 5, a = - 1 or 1, D is correct

How to calculate 1-A & # 178; B & # 178,

Factorization?
1-a²b²=（1+ab)(1-ab)
Basis: square difference formula

Compare size 4 + 3 ^ 2-2b + B ^ 2 with 3A ^ 2-2b ^ 2 + 1
Urgent, help me solve it quickly! Note: request difference method comparison

The difference method compares the size of 4 + 3A ^ 2-2b + B ^ 2 with 3A ^ 2-2b + 1
To compare the size of the difference Oh!