Solving the fractional equation: 2x2x + 5 − 55x − 2 = 1

Solving the fractional equation: 2x2x + 5 − 55x − 2 = 1

2x2x + 5 − 55x − 2 = 1.2x (5x − 2) (2x + 5) (5x − 2) − 5 (2x + 5) (2x + 5) (5x − 2) = 1, 2x (5x − 2) − 5 (2x + 5) (2x + 5) (5x − 2) = 1, 10x2-14x-25 = 10x2 + 21x-10, - 35x = 15, x = - 37

If 2x = 43 and 3 (x + a) = a-5x have the same solution, then A-1 = 1___ ．

Solve the equation 2x = 43 to get: x = 23, substitute x = 23 into 3 (x + a) = a-5x to get the equation about a: - 6A = 16 to get: a = - 83, substitute a = - 83 into A-1 to get: A-1 = - 113

A cylindrical iron block with a circumference of 15.7 cm and a height of 10 cm is fused into a cone. If the bottom area of the cone is 25 square cm, what is its height?

5 (CM), 3.14 × 2.52 × 10 × 3 / 25, = 3.14 × 6.25 × 10 × 3 / 25, = 588.75 / 25, = 23.55 (CM); a: the height of the cone is 23.55 cm

87.5 × 23 + 7 / 8 is not the formula for solving the equation!
87.5% × 23 + 7 / 8 [how is there a simple method?] is not the formula for solving the equation! [wrong type above, 87.5 has a percent sign]

0.875*23 0.875*1
0.875*（23 1）
0.875*24
twenty-one

Why to find the range of the function f (x) = 3 + lgx + 4 / (lgx) (x > 0 and X is not equal to 1? All the ranges should not be omitted

First, because x > 0 and X is not equal to 1
So lgx ∈ (- infinity, 0) ∪ (0, + infinity)
When lgx > 0, according to the formula a + B ≥ 2 radical (AB), then lgx + 4 / (lgx) ≥ 2 radical 4 = 4, so if and only if lgx = 4 / (lgx), that is, x = 100, f (x) = 3 + lgx + 4 / (lgx) takes the minimum value of 7 when lgx > 0
When lgx

The length of the top and bottom of the trapezoid is xcm, the length of the bottom is 1cm less than twice of the top and the height is 1cm

① Expressing trapezoidal area with algebraic formula containing x
S=(x+(x+1)/2)*1/2=(3x+1)/4
② If x = 3, find the area of this trapezoid
(3 * 3 + 1) / 4 = 2.5 square centimeter

Twenty four points: using two different methods, the four numbers 3, 4, - 6 and 10 are calculated by four operations (each number is used and only used once), so that the result = 24
Using two different methods, four numbers 3,4, - 6,10 are calculated by four operations (each number is used and only once), so that the result is equal to 24

10 - 4 - [(-6) ×3]
＝10-4-（-18）
＝10-4+18
＝6+18
＝24
3 × (10 - 4) - (-6)
＝3×6-（-6）
＝18-（-6）
＝18+6
＝24

Let the sum of the first n terms of the sequence {an} be SN. If {Sn} is an equal ratio sequence with S1 as the first term, all of them are positive numbers and Q as the common ratio
1) Find the general term formula an of sequence {an} (expressed by S1 and Q);
2) Compare an + an + 2 with 2An + 1 and prove your conclusion

S (n) = s (1) Q ^ (n-1), s (n) > 0. When a (1) = s (1), a (n + 1) = s (n + 1) - S (n) = s (1) [Q ^ (n) - Q ^ (n-1)] = (Q-1) s (1) Q ^ (n-1), a (1) = s (1), n > = 2, a (n) = (Q-1) s (1) Q ^ (n-2). When n = 1, a (1) + a (3) - 2A (2) = s (1) + (Q-1) s (1) Q-2 (Q-1) s (1) = s (1) [3-3q + Q ^ 2] = s (1) [3

The area of a square is 81 square decimeters. What is its perimeter?
It's not enough

How to calculate 1.11 × 9.9 + 8.88 × 8.9?
How much is seven eighths times eight?

1.11 × 9.9 + 8.88 × 8.9 = 1.11 × 9.9 + 1.11 × 8 × 8.9 = 1.11 × (9.9 + 71.2) = 1.11 × 81.1 = 90.0217 / 8 × 8 = 7 ~ Li from the primary school attached to normal university answers for you ~ ~ if you are satisfied, please press accept, your adoption is my driving force~