A, B, C and D donate to a disaster area. A's donation is 13% of the total donation of the other three people. B's donation is 15% of the total donation of the other three people. C's donation is 16% of the total donation of the other three people. D's donation is 148 yuan. How much yuan did a donate?

148 △ 1-13 + 1-15 + 1-16 + 1) × 13 + 1 = 148 △ 1-14-16-17) × 14, = 148 △ 3784 × 14, = 336 × 14, = 84 (yuan); answer: a donated 84 yuan

The top of trapezoid is 1.5 times of the bottom, the height is 18 cm and the area is 540 square cm
It's better not to use the equation
Where did the bottom formula come from?

Because trapezoid area = (upper bottom + lower bottom) * height / 2
So the bottom and the top is 540 * 2 / 18 = 60
The bottom is equal to 60 / (1 + 1.5) = 24
The upper and bottom are equal to 60-24 = 36

Fifth grade holiday paradise happy summer vacation mathematics page 42
When Xiao Wei was calculating (6 + ()) * 3, he mistakenly wrote the formula as (6 + () * 8), so his result was better than the correct one
sorry! Then the above topic is:
It's 45 more than the correct number. What's the number in ()?

You are so wrong

For rational numbers x and y, a new operation x * y = ax + by + C is defined, where a, B and C are constants. On the right side of the equation are the usual addition and multiplication operations. Given that 1 * 2 = 9, (- 3) * 3 = 6, 0 * 1 = 2, find the value of (- 2) * 5

From the meaning of the title: a + 2B + C = 9-3a + 3B + C = 6B + C = 2, the solution: a = 2B = 5C = - 3. Therefore, the new operation is x * y = 2x + 5y-3

What is 5 minus 8 out of 27

5-8/27
Solution = 4 + (1-8 / 27)
=4 and 19 / 27
If you have any questions, please ask,
If you are satisfied with my answer
This is your greatest affirmation of me,

X + 2Y + xy = 77, x, y are integers, find the value of X + y

xy+x+2y=77
x(y+1)+2y=77
x(y+1)+2(y+1)=79
(x+2)(y+1)=79
79 is a prime number, which can only be decomposed into 1 × 79 or - 1 × - 19
Four cases
1)
x+2=1
y+1=79
figure out
x=-1,y=78
2)
x+2=79
y+1=1
The solution is x = 77, y = 0
3)
x+2=-1
y+1=-79
The solution is x = - 3, y = - 80
4)
x+2=-79
y+1=-1
The solution is x = - 81, y = - 2
If you still have any questions, please ask!

Li Ming goes to buy shampoo. There are different promotion methods in the two supermarkets. In supermarket a, each bottle is 28 yuan, five for one free. In supermarket B, each bottle is 28 yuan, 70% off. Li Ming wants to buy 5 yuan

Then buy B supermarket, or it's a waste if you can't use it up!

X ＞ 0, y ＞ 0 and X / 2 + Y / 8 = 1

4X + y = 8 > = 2 * 2 radical XY
Radical XY

How to write hamburger in English

Hamburger

Two times one in four plus three times one in five plus four times one in six plus Nine times one in eleven

Split term method
Two times one in four plus three times one in five plus four times one in six plus Nine times one in eleven
=1/2×（1/2-1/4+1/3-1/5+1/4-1/6+…… +1/9-1/11）
=1/2×（1/2+1/3-1/10-1/11）
=1/2×106/165
=53/165

The top of trapezoid is 1.5 times of the bottom, the height is 18 cm and the area is 540 square cm It's better not to use the equation Where did the bottom formula come from?