222 ÷ 18 + 777 × 4 / 63 + 999 × 4 / 81, calculate with your favorite method

222 ÷ 18 + 777 × 4 / 63 + 999 × 4 / 81, calculate with your favorite method

222 △ 18 + 777 × 4 / 63 + 999 × 4 / 81
=111×1/9+111×4/9+111×4/9
=111×（1/9+4/9+4/9）
=111×1
=111

2 (3x + 15) - 2x = 76 to solve the equation

2（3x+15)-2x=76
6x+30-2x=76
6x-2x=76-30
4x=46
x=46/4
x=11.5

Degree minute second conversion
45 ° conversion___ °___ '___”
143 ° 18'54 "transformation_______ °
Can you talk about the process

45.45°= 45°27′0〃
143°18′54〃=143.315°
Baidu Hi~

The function f (x) = ax ^ 2 + bx-4, where a, B and 4 are in equal proportion sequence, then the minimum value of function f (x) is

Then B & sup2; = 4A
Obviously, 4A > 0
a>0
b=±2√a
f(x)=ax²±2√ax-4
=a(x±√a/a)²-5
a>0
So the minimum value = - 5

What is 4.875-3 and 11 out of 12

875-3 and 11 out of 12
=4 and 7 in 8-3 and 11 in 12
=39 / 8-47 / 12
=117 out of 24-94 out of 24
=23 out of 24

Let a = (SiNx, 34), B = (13, 12cosx), and a ‖ B, then x is___ ．

∵ vector a = (SiNx, 34), B = (13, 12cosx), and a ∥ B, ∥ 14-12sinxcosx = 0, so sin2x = 1 ∥ 2x = 2K π + π 2 (K ∈ z), the solution is x = k π + π 4, (K ∈ z), so the answer is k π + π 4, (K ∈ z)

Among the following substances, the one that can be stably preserved in air is ()
A. NaOH solid B. dilute h2so4c. Na2SO3 crystal D. bisulfuric acid

A. Sodium hydroxide can absorb water and carbon dioxide in the air, and generate sodium carbonate and water, which makes sodium hydroxide deteriorate and cannot be stably stored in the air, so a is wrong; B. nitrogen, oxygen, carbon dioxide, water vapor, etc. in the air do not react with dilute sulfuric acid and can be stored in the air for a long time, so B is correct; C. sodium sulfite is unstable and easy to be oxidized by oxygen in the air Gas oxidation generates sodium sulfate, so sodium sulfite cannot be stored in the air for a long time, so C is wrong; D. hydrogen sulfuric acid is easily oxidized by oxygen in the air to generate sulfur, so hydrogen sulfuric acid cannot be stored in the air for a long time, so D is wrong; so B is selected

Given circle C1: X Λ 2 + y Λ 2 + 4x + 3 = 0 (1), if circle C2 is circumtangent to circle C1 and tangent to line L: x = 1, find circle C2

Circle C1: X Λ 2 + y Λ 2 + 4x + 3 = 0: (x + 1) & #178; + y ^ 2 = 1
C1(-1,0),R1=1
∵ circle C2 is circumscribed with circle C1 and tangent to line L: x = 1
When C2 is on the x-axis,
C2(1/2,0),R2=1/2
Circle C2: (x-1 / 2) &# 178; + Y & # 178; = 1 / 4
Let C2 (x, y) (x) at any time

A number divided by 3 to 2, divided by 5 to 3, divided by 7 to 2, at least how much is this number? How to write this formula

Three people walking together
Twenty one plum trees
Members of the seventh Youth League
Except one hundred and five
For example:
2×70+3×21+15×2=233,
Subtract the multiple of 105, that is 210,
It's 23. That's 23

On the equation x & # 178; + 5x + M = 0 of X, which has two imaginary roots X1 and X2 and satisfies | x1-x2 | = 3, what is the value of real number m?

The discriminant △ is 25-4m