How to solve this equation

How to solve this equation

(2.3 x)*6=12
2.3*x=2
x=2/2.3=20/23=0.87

The number of 3.6 is 12.6, which is more than 45% of a number? (solve with equation) 2. The sum of a and B is 12. A is 13 of B. what are the numbers a and B?

(1) Let this number be X. according to the meaning of the question, we get 45% x + 3.6 = 12.6 & nbsp; & nbsp; 0.45X = 12.6-3.6 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 9 △ 0.45 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 20 A: this number is 20. (2) 12 △ 1 + 13) = 12 × 34 = 912-9 = 3 A: number a is 3, number B is 9

It is known that the ellipse x2 / 100 + Y2 / 64 = 1 has an inscribed rectangle ABCD to calculate the maximum area of rectangle ABCD

Let any point (x, y) on the ellipse, because there is a point (x, y) on the ellipse
The two variable lengths of the rectangle are 2x and 2Y respectively. So the area of the rectangle is 4xy. 4xy = 2Ab * [2 (x / a) (Y / b)] ≤ 2Ab * [(x / a) &# 178; + (Y / b) &# 178;] = 2Ab * 1 = 2Ab
For this question, Smax = 2x10x8 = 160

Do not change the order of the six numbers in 1.2.3.4.5.6, add operation symbols, so that the number after calculation is 20

1*2*3+4*5-6=20
1*（2+3+4+5+6）=20

Given the function f (x) = 1-2ax-a2x (a > 1) (1) find the range of function f (x); (2) if x ∈ [- 2, 1], find the minimum value of function f (x) - 7, find the value of a and the maximum value of function f (x)

Let't = t ＞ 0 \ \\\\\\\\ (1, + ∞) \\\\\\\\\\\\\\\ (1 \8713; (1 (1, + ∞ (1, + ∞) \\\\\\\\\\\\\\\\\\\\\\at14, y has the maximum value, that is, ymax = - (14) ）2-2×14+1=716

Ellipse and hyperbola have common focus, ellipse 25X ^ 2 + 9y ^ 2 = 255, the sum of their eccentricity is 2

The eccentricity of ellipse is 0

Define a new operation: a * b = a + B, simplify: (a ^ 2) * (3AB) + 5A ^ 2b-4ab

Because a * b = a + B
So: (A & # 178;) * (3AB) = A & # 178; + 3AB
(a²)*(3ab)+5a²b-4ab
=a²+3ab+5a²b-4ab
=a²-ab+5a²b

If we know that the tangent at a point m on the 5th power of the curve y = 1 / 5x is perpendicular to y = 3-x, then the tangent equation is?
I need it urgently,

Y '= X4 power! Then y' | x = x, = 1 gets x, = plus or minus 1! So the tangent coordinates are (1,1 / 5) and (- 1, - 1 / 5). So there should be two corresponding tangent equations

-24+|3-4|-2×（-1）2006．

The original formula = - 16 + 1-2 = - 17

What do the letters used in the arithmetic sequence formula represent? For example, A1 represents the first term, what about the others

I'm glad to answer your question
The formula of arithmetic sequence: an = a1 + (n-1) d;
N is the number of items
A1 first item
An is the general formula of the nth term,
D is the tolerance