6 (x 3.2) = 48.6, 5 (x-3) = 55

6 (x 3.2) = 48.6, 5 (x-3) = 55

6(x 3.2)=48.6
x+3.2=48.6÷6
x+3.2=8.1
x=8.1-3.2
x=4.9
5（x-3）=55
x-3=55÷5
x-3=11
x=11+3
x=14

X + 55 = 3.2X

x+55=3.2x
55=（3.2-1）x
55=2.2x
2.2x=55
x=55÷2.2
x=25
Simple!

By solving the equation x / (x + 0.55) = 1.4/1.6, x = 3.85

X/(X+0.55)=1.4/1.6
1.6X=1.4(X+0.55)
1.6X=1.4X+1.4*0.55
0.2X=1.4*0.55
X=7*0.55
X=3.85
We may have to talk about it in grade six of primary school, and learn it formally in grade two of junior high school. This kind of equation is called fractional equation

As shown in the figure, it is known that the bottom radius of the large cone is r, the generatrix length is 2R, and the side area of the small cone is half of the side area of the large cone?
Urgent! Good people help!

The formula of cone side area s = π × L × R
Side area of large cone s = π× (2 π R) × R
Side area of small cone s' = s / 2 = (π × 2 π R × R) / 2 = π × π × R × R
The side area of small cone is also equal to s' = π × 2 π R × R
Because s' = s'
So π × π × R × r = π × 2 π R × R
Then: r = under the root sign (R × R / 2)

The mean of sample x, y, 99100101 is 100, the variance is 2, and the value of ball x, y is known

x+y+99+100+101=100*5
-> x+y=200 y=200-x
(x-100)^2+(y-100)^2+1+0+1=2*5
-> (x-100)^2+(100-x)^2=8
|x-100|^2=4
|x-100|=2
x=102,y=98 or x=98,y=102

Solution inequality: LG (4 + 3x-x ^ 2) - LG (2x-1) > LG2

lg(4+3x-x^2)-lg(2x-1)>lg2
lg[(4+3x-x²)/(2x-1)]>lg2
(4+3x-x²)/(2x-1)>2
2-(4+3x-x²)/(2x-1)

If the circumference of a circle is equal to that of a square, the area of the circle is larger than that of the square______ (judge right or wrong)

Suppose the circumference of circle and square is 12.56 cm, then the side length of square is a = C △ 4 = 12.56 △ 4 = 3.14 (CM), the area of square is s = A2 = 3.14 × 3.14 = 9.8596 (CM), the radius of circle is r = C △ 2 π = 12.56 △ 4 = 2 (CM), the area of circle is s = π R2 = 3.1

It is known that a = 3 and 1 / 2, B = 1 / 2, C = D × 15 / 14 = 4 and 1 / 3 will arrange ABCD from small to large

C = D * (14 / 15) = 4 and 1 / 3
The solution is d = 4 and 9 / 14
So B

How to find the degree and coefficient of polynomial?

The degree of this polynomial is 3. That is to look at the degree of the monomial in this polynomial one by one. The degree of the monomial is 3, which is also the highest degree of the polynomial. Then the polynomial takes its degree
Coefficient refers to the number before the letter in each monomial (excluding the constant term, which is a number) of a polynomial, but pay attention to the sign before that number

How to make an arc with a chord length of 1800 on the radius of a known circle

Use trigonometric function to calculate, make a line at the middle point of the chord length to connect with the center of the circle to form a right triangle with known hypotenuse and a right angle. Then calculate the corresponding angle (the angle between the radius and the line) according to trigonometric function, so the arc length formed by 2 times of the included angle is the corresponding arc length of the chord length!