A formula with unknowns is called an equation ()

A formula with unknowns is called an equation ()

An equation with unknowns is called an equation
An equation with unknowns is called an equation

Is a formula with unknowns called an equation?

No, it's wrong

Circumference of circle = () * (), indicated by letters; C = ()

Circumference of a circle = (PI) * (diameter), expressed in letters; C = (π d)

When x > 1, it is proved that ex > ex

In order to prove that when x > 1, ex > ex, we only need to prove that ex ex ex > 0. Let f (x) = ex ex, then f (1) = 0. Because f '(x) = ex-e, when x > 1, f' (x) > 0, thus f (x) > F (1) = 0, that is, when x > 1, ex ex ex > 0

Xiao Hong read a story book. She read 3 / 10 of the whole book on the first day, 4 / 5 of the first day and 48 pages on the second day. How many pages is the story book?
Mr. Wang and Mr. Li cooperated to produce a batch of parts. Mr. Wang produced 105 parts, accounting for 3 / 7 of the total number of parts. Mr. Li produced 2 / 5 of the total number of parts. How many parts did Mr. Li produce?
A train goes from place a to place B at the speed of 85 kilometers per hour, 2 / 7 of the whole journey in 2 / 5 hours?

Xiao Hong read a story book. She read 3 / 10 of the whole book on the first day, 4 / 5 of the first day and 48 pages on the second day. How many pages is the story book?
48÷4/5÷3/10
=60÷3/10
=200 pages
Mr. Wang and Mr. Li cooperated to produce a batch of parts. Mr. Wang produced 105 parts, accounting for 3 / 7 of the total number of parts. Mr. Li produced 2 / 5 of the total number of parts. How many parts did Mr. Li produce?
105÷3/7×2/5
=245×2/5
=98
A train goes from place a to place B at the speed of 85 kilometers per hour, 2 / 7 of the whole journey in 2 / 5 hours?
85×2/5÷2/7
=34÷2/7
=119 km

A 0.125 cm3 cube aluminum block was cast into eight small cubes of the same size, and the surface area of each small cube aluminum block was calculated

Let the edge length of a small cube be xcm, then 8x3 = 0.125. The solution is: x = 14, then the surface area of each small cube aluminum block is 6 × (14) 2 = 38 (CM). A: the surface area of each small cube aluminum block is 38cm

If the real number a square + 4B square + C square = 1, then the value of a + B + C is the maximum

Let y = y (x) be determined by y-xe ^ y = 1

y-xe^y=1
y ' - [x ' e^y + x（e^y）'] = 0
y ' - [ e^y + x y ' e^y ] = 0
（1 - x e^y）y ' = e^y
y ' = e^y /（1 - x e^y）

Application of plane vector
In the plane rectangular coordinate system, it is known that the coordinates of the three vertices of the triangle ABC are a (2,3), B (1, - 1), C (5,1). Point P moves on the straight line BC, and the moving point Q satisfies the vector PQ = vector PA + vector PB + vector PC, then the trajectory equation of point q is
A x-2y+4=0 B x+y=0 C 2x-y+3=0 D x+y-2=0

If you choose a, you can calculate it by substituting it

Given the function f (x) = cos2x + asinx-2a-2, (I) when a = - 2, X belongs to (Pie / 6,2 Pie / 3) range? What is the value of a, FX = (a + 1) SiNx in [0,2 pie]

&Let t = SiNx be a [- 1,1] & nbsp; subequation with only one solution on [- 1,1] and ≠ plus or minus 1. Let H (T) = - (T + 1 / 2) ^ 2 + 1 / 4H (- 1) = 0 & nbsp; H (1) = - 2 & nbsp; H (- 1 / 2) = 1 / 4-2 ＜ 2A + 1 ＜ 0 or 2A + 1 = 1 / 4