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Seven out of twenty divided by three out of five, six out of seven divided by 12, five out of sixteen divided by seven out of eight, twelve divided by four out of five
Seven out of twenty divided by three out of five = seven out of twelve,
Six out of seven divided by 12 = one out of 14,
5 out of 16 divided by 7 out of 8 = 5 out of 14,
Twelve divided by four fifths = 15
Five eighths divided by five thirds + three fifths multiplied by three eighths
Five eighths divided by five thirds + three fifths multiplied by three eighths
=5/8×3/5+3/5×3/8
=（3/5×（5/8+3/8）
=3/5
(2 and one quarter minus 1 and three fifths) * 1.6 divided by (182 * one seventh)
=(2.25-1.6)*1.6÷26
=0.65*1.6÷26
=1.04÷26
=0.04
A problem of five means inequality in high school mathematics
Given a > 0, b > 0, a + B = 1, prove (a + 1 / a) (B + 1 / b) ≥ 25 / 4
The passenger and freight cars start from a and B at the same time, and run in opposite directions. Five hours later, they meet at the midpoint of the two places, 30km away. Given that the speed ratio of the passenger and freight cars is 5:7, what is the distance between a and B?
30 × 2 ^ (75 + 7-55 + 7) = 60 ^ 212 = 360 km a: the whole journey is 360 km
On the usage of basic inequality
Why must one side be a fixed value when using the basic inequality to find the maximum value?
Please help
THANKS～
Because it's an inequality. If one side is not fixed, how can we get the maximum value
Both passenger and freight cars leave from a and B at the same time. It takes 10 hours for the passenger car to complete the whole journey, and 15 hours for the freight car to complete the whole journey. After the two cars meet, the passenger car runs 96 hours again
At this time, the bus made 80% of the whole journey
Encounter time = 1 ÷ (1 / 10 + 1 / 15) = 6 hours
At this time, the whole journey of the bus is 6 / 10 = 3 / 5
Whole journey = 96 ÷ (80-3 / 5) = 480km
In the coordinate system of mathematical projection space, if Z is a constant, what is its projection in xoz YOZ
If Z is a constant, what is its projection on xoz YOZ? For example, how does z = e ^ a come from
|P(x)|^2 = x^2 + y^2,|P(y)|^2 = y^2 + z^2,|P(z)|^2 = z^2 + x^2 L^2 = x^2 + y^2 + z^2 = [|P(x)|^2 + |P(y)|^2 + |P(z)|^2]/2,L>0z^2 = L^2 - |P(x)|^2,x^2 = L^2 - |P(y)|^2,y^2 = L^2 - |P(z)|^2,cos(X)=x/L,c...
The ratio of group A and group B is 5:3. If 4 people are transferred from group A to group B, the ratio of group A and group B is 3:2. How many people are there in the two teams
There were 5x people in group A and 3x people in group B
(5x-4):(3x+4)=3:2
10x-8=9x+12
x=20
5x=100
3x=60
100 in group A and 60 in group B
From the 50 natural numbers from 1 to 50, add two numbers so that their sum is greater than 50______ There are two different methods
49+47+45+43+… +1, = (1 + 49) × 25 ÷ 2, = 25 × 25, = 625 (species); answer: take two numbers from the 50 natural numbers from 1 to 50, and there are 625 different ways to make their sum greater than 50; so the answer is: 625
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