The binary linear equation 2x + 3y-4 = 0 is changed into the form of y = KX + m, and the value of 2K + 5m is obtained

The binary linear equation 2x + 3y-4 = 0 is changed into the form of y = KX + m, and the value of 2K + 5m is obtained

2x+3y-4=0
3y=-2x+4
y=(-2/3)x+4/3
y=kx+m
Then:
k=-2/3；m=4/3
2k+5m=-4/3+20/3=16/3

If the bivariate linear equation 2x + 3y-5 = 0 is changed into the form of y = KX + B, then B / K=

3y=-2x+5
y=-2/3 x + 5/3
k=-2/3
b=5/3
So: B / k = - 5 / 2

Draw the largest circle in a square of 24 square cm. The circumference of the circle is () cm and the area is () square cm

Draw the largest circle in a square of 24 square cm. The circumference of the circle is (75.36) cm and the area is (452.12) square cm
Radius = 24 / 2 = 12cm
Perimeter = 2x12x3.14 = 75.36cm
Area = 12x12x3.14 = 452.16 square centimeter

How to calculate the side area of a triangular prism?

Prisms can be divided into straight prisms and oblique prisms
Perimeter of base × height of prism

Know chord length and radius, find arc length

Arc length = n * π * r / 180`
N is the degree of the angle of the center of the circle
π is 3.14
R is the radius
If π and R are known, only n is unknown, and the chord length and two adjacent radii form a triangle, the degree n of the central angle of the circle can be obtained

Sum: SN = 1-5 + 9 - +(-1)^(n-1)(4n-3)
Please use the method of double difference summation to do it. We must use double difference summation,

Let Sn = s' + s' ', where ① s' = 1 + 9 + 17 + +(8m-7), that is, the sum when n is odd; ② s' '= - 5 - 13 - 21 - -(8m-3), that is, the sum when n is an even number; Formula 1 is an arithmetic sequence, the difference is 8, M = n / 2 (when n is an even number) or M = (n-1) / 2 + 1 (when n is an odd number)

The lines of an ancient poem

Berthing a boat on Guazhou
Wang Anshi (Song Dynasty)
There is a water room in Guazhou, Jingkou,
Zhongshan is only a few mountains apart
The spring breeze is green on the South Bank of the river,
When will the moon shine on me?

Given that the absolute value of the equation x ^ 2 / M-1 + y ^ 2 / 2-m = 1 represents an ellipse with focus on the y-axis, the value range of M is determined

According to the meaning of the title
Elliptic equation: X & sup2; / (/ M / - 1) + Y & sup2; / (2-m) = 1
// represents the absolute value
2-m>0(1)
/m/-1>0(2)
2-m>/m/-1(3)
From (1) M1 or M0
2-m>m-1
2m-1 Hengcheng
So 0 ≤ M

The circumference of a rectangle is 48 cm, and the ratio of length to width is 5:3. What is the area of a rectangle?
There are 120 more bulls than calves in the cattle farm. If the number of calves accounts for 3 / 4 of the calves, how many calves and calves each have?

Length = 48 / 2 * (5 / (5 + 3)) = 15, width = 48 / 2-15 = 9
Area = 15 * 9 = 135
Daniel = 120 / (1-3 / 4) = 480 calf = 480-120 = 360

If 0 < β < α < π 2 and COS (α + β) = 45, sin (α − β) = 513, then the value of Cos2 α is ()
A. 6365b. − 6365c. 3365d. 5665 or − 1365

So sin (α + β) = 1 − (45) 2 = 35, cos (α - β) = 1 − (513) 2 = 1213, and Cos2 α = cos [(α + β) + (α - β)] = cos (α + β) cos (α - β) - sin (α + β) sin (α - β) = 45 × 1213