1 / 4:1 / 7 = 1 / 3: (4-x) how to solve this equation?

1 / 4:1 / 7 = 1 / 3: (4-x) how to solve this equation?

1/4:1/7=1/3:(4-x)
1/4(4-x)=1/7*1/3
Double four on both sides
4-x=4/21
x=4-4/21
x=80/21

How to solve x (x + 1) - x (x-1) = 188,

x^2+X-X^2+X=188,X=94

The solution of X + X + (188-x) + (180-x) = 368 x

x+x+(188-x)+(180-x)=368
2x+188-x+180-x=368
368=368
The solutions of the original equation are all real numbers

Given that f (x + 2) = x-4x-7, X belongs to [- 4,4], find the range of F (x)

F (x + 2) = x-square-4x-7 = (X-2) & #178; - 11
Let t = x + 2, x = T-2
f(t)=(t-4)²-11
When x belongs to [- 4,4], the range of F (x) [- 11,53]

How to do the 19 questions on page 14 of the first volume of junior high school mathematics full product exercise book!

Stick it up

3.7.19.55.163 what's the rule

2(3^(n-1)-1)+3

The volume of a basketball is 3930 π cm3, and the radius r of the basketball is calculated. (the volume of the ball is v = 43 π R3, accurate to 1cm.)

∵ 43 π R3 = 3930 π, ∵ r = 33930 π × 34 π≈ 14 (CM)

Each piece of aluminum can be used to make 16 bottles or 43 bottles bottom, and one bottle body can be equipped with two bottles bottom. There are 150 pieces of aluminum. How many bottles body and how many bottles bottom can be used to make a complete set of beverage bottles?

If x pieces of aluminum are used as the bottle body, then (150-x) pieces of aluminum are used as the bottle bottom. According to the meaning of the question, we can get 2 × 16x = 43 × (150-x). If x = 86, then 150-86 = 64 pieces of aluminum are used as the bottle bottom. Answer: if 86 pieces of aluminum are used as the bottle body, then 64 pieces of aluminum are used as the bottle bottom

Observe the following arrangement rule, the natural number 1000 is the number () from the left of the () line
one
2 3
4 5 6
7 8 9 10
11 12 13 14 15

Line 45, 10th

What is the sum of all integers with absolute values greater than 2 but less than 7

3+4+5+6+(-3)+(-4)+(-5)+(-6)=0