Fruit Aunt Li brought some apples and pears. The mass ratio of apples and pears is 3:1. Apples are 120kg more than pears. How many kilograms are there in total?

Fruit Aunt Li brought some apples and pears. The mass ratio of apples and pears is 3:1. Apples are 120kg more than pears. How many kilograms are there in total?

3-1=2
120/2=60（kg）
3+1=4
60*4=240（kg）
Thank you

The fruit shop brought 600 kg of apples, pears and oranges. Apples are 80 kg less than pears, and oranges are three times more than pears
The fruit shop shipped 600 kg of apples, pears and oranges. The apples were 80 kg less than the pears, and the oranges were 20 kg more than the pears?

The fruit shop shipped 600 kg of apples, pears and oranges. The apples were 80 kg less than the pears, and the oranges were 20 kg more than the pears?
Let the pear be X
Then Apple = 2x-80
Orange = 3x + 20
x+2x-80+3x+20=600
6x=660
x=110
Pear 110 kg, apple 140 kg, orange 350 kg

Auntie Zhang and auntie Li took out the same money and bought a box of pears. Auntie Zhang divided 8 kilograms, and auntie Li only had 5 kilograms. As a result, Auntie Zhang paid auntie Li 4 or 2 yuan. How much yuan per kilogram of pears?
In a hurry! Answer that day

Aunt Zhang took three catties more than Aunt Li and paid 4.2 yuan more. We can see that 4.2/3 per kilogram of pears is 1.4 yuan!

As shown in the figure: to build a road with the same width on a rectangular green space with a length of 100 m and a width of 90 m, and the total area of six green spaces is 8448 m2, the width of the road is___ ．

Let the width of the road be XM, according to the equation of the meaning of the problem, we can get ｛ (100-2x) (90-x) = 8448, we can get x2-140x + 276 = 0, we can get X1 = 2, X2 = 138 (not practical, omit); so the answer is 2m

8 / 3 to 16 / 9

Multiply by 9
=24:16
Divide by 8
=3:2
Ratio = 3 △ 2 = 1.5

{an} is an arithmetic sequence, the first term A1 > 0, A2010 + A2009 > 0, A2010 · A2009

∵a2010·a20090,
Ψ decreasing arithmetic sequence, tolerance Q0, a20100, A2010 = a1 + 2009q0
∴2a+4017q>0
Sn=(a1+an)n/2=(a1+a1+(n-1)q)n/2=(2a1+(n-1)q)n/2
Sn > O means (2A1 + (n-1) q) n / 2 > 0
A1 > 0, n is a natural number
Do not wait until the formula (2A1 + (n-1) q) n / 2 > 0 becomes 2A1 + (n-1) Q > o
From 2A1 + 4017q > 0, 2A1 + 4018q = 2 (a1 + 2009q)

The school lays the floor brick for the electric classroom. It needs 400 square bricks with a side length of 30 cm. If we use square bricks with a side length of 60 cm instead
How many bricks do you need to buy?

60/30=2
2x2=4
400 / 4 = 100 pieces

The customs of 56 nationalities!

In the 13th century, a large number of Muslims moved to China from Central Asia and integrated with the local Han, Uygur, Mongolian, etc. in the long historical process, through intermarriage and other factors, they gradually formed the Hui nationality

Tan θ = 2, sin θ square + 2Sin θ cos θ + 1

Application of universal formula
sinα=[2tan(α/2)]/{1+[tan(α/2)]^2}
cosα=[1-(tan(α/2))^2]/{1+[tan(α/2)]^2}
cos2θ=[1-(tanθ)^2]/[1+(tanθ)^2]=(1-4)/(1+4)=-3/5
sin2θ=2tanθ/(1+(tanθ)^2)=4/(1+4)=4/5
Sin θ squared = (1-cos2 θ) / 2,2sin θ cos θ = sin2 θ
Sin θ square + 2Sin θ cos θ + 1 = (1-cos2 θ) / 2 + sin 2 θ + 1 = (1 + (3 / 5)) / 2 + 4 / 5 + 1 = 13 / 5

The length of three sides of a right triangle is 3cm, 4cm and 5cm respectively. What is the height of the hypotenuse of the triangle?

According to the equal area of triangles, 1 / 2 * 3 * 4 = 1 / 2 * 5 * HH = 12 / 5h = 2.4 (CM)