(x + 1) & #178; - 2 (x + 1) = 3 the main process of solution

(x + 1) & #178; - 2 (x + 1) = 3 the main process of solution

(x+1)²-2(x+1)=3
(x+1)²-2(x+1)-3=0
[(x+1)-3][(x+1)+1]=0
(x-2)(x+2)=0
X = 2 or x = - 2

4（x＋3）²=25（x－2）²

2 (x + 3) = 5 (X-2) or 2 (x + 3) = - 5 (X-2)
2X + 6 = 5x-10 or 2x + 6 = - 5x + 10
-3x = - 16 or 7x = 4
X = 16 / 3 or x = 4 / 7

（x-1/x²+6x+9）÷（x²-1/x+3）=（x+1/2）

(x-1 / X & # 178; + 6x + 9) / (X & # 178; - 1 / x + 3) = (x + 1 / 2) reduction
（x-1）/（x＋3）²÷（x－1）*（x+1）/（x+3）=（x+1/2）
1/（x+1）（x+3）=（x+1/2）
Are you (x + 0.5) or (x + 1) / 2?

As shown in the figure, AB is the diameter of ⊙ o, BC is the tangent of ⊙ o, D is a point on ⊙ o, and BD ∥ Co. (1) prove: △ ADB ∥ CBO; (2) if AB = 2, BC = 2, find the length of AD (the result retains the root sign)

(1) It is proved that: ∵ AB is the diameter of circle O, ∵ d = 90 °, BC is the tangent of circle O, ∵ ABC = 90 °, ∵ d = ∥ ABC, DB ∥ OC, ∵ abd = ∥ cob, ∥ ADB ∥ CBO; (2) let ad = x, in the right triangle abd, from ab = 2, ad = x, according to the Pythagorean theorem: DB = 4 − X2, from

Given that line segment AB = 8cm, point C is any point on line segment AB, and points m and N are the midpoint of line segment AC and line segment BC respectively, the length of line segment Mn is calculated

∵ point m is the midpoint of AC, ∵ MC = 12ac, ∵ point n is the midpoint of BC, ∵ CN = 12bc, Mn = MC + CN = 12 (AC + BC) = 12ab = 4

As shown in the figure, the known point a is a trisection point on the semicircle with Mn as the diameter, point B is the midpoint of an, and point P is the point on the radius on. If the radius of ⊙ o is l, then the minimum value of AP + BP is ()
A. 2B. 2C. 3D. 52

Make a symmetric point a 'of point a about Mn, connect a' B, intersect Mn at point P, then PA + Pb is the smallest, connect OA ', AA', ob, ∵ point a and a 'are symmetric about Mn, point a is a trisection point on semicircle, ∵ a' on = ∠ AON = 60 °, PA = PA ', ∵ point B is the midpoint of arc an ^, ∵ Bon = 30 °, ∵ a' O

If the solution of equation (2x + a) / (X-2) = 1 is positive, the range of a is obtained
For this question, one student gave the following answers:
Solution: remove the denominator, get 2x + a = - x + 2, simplify, get 3x = 2-A, so x = (2x-a) / 3
If the heel of the equation is positive, it must be (2-A) / 3 > 0, and a is obtained

Error! Incomplete
The first step is to treat a as a constant and solve the equation: x = (2x-a) / 3
Step 2: the stem of the problem says that the solution is a positive number, that is, X is a positive number, so: x = (2x-a) / 3 > 0, so: (2-A) / 3 > 0
Step 3: solve the linear inequality of one variable about ah to get: a

Given the hyperbola 2x2-y2 = 2, the line L passing through the point P (2,1) intersects the hyperbola at two points a and B. if the line AB is parallel to the y-axis, the length of the line AB is calculated

By substituting the straight line x = 2 into the hyperbola 2x2-y2 = 2, we can get y = ± 6, and the length of the line AB is 26

If the value of polynomial 3x ^ 2 + X + 2 is 5, then the value of polynomial 6x ^ 2 + 2x-3 is 5

6X^2+2X-3=2(3X^2+X+2)-7=2*5-7=3

In the tetrahedral ABCD, ab = 1, CD = 2, the distance between the straight line AB and CD is 2 √ 2, then the maximum volume of the tetrahedral ABCD is 0
The answer is 2 √ 2 / 3

Let the common perpendiculars of AB and CD intersect AB at e and CD at F, and connect CE and de. it is obtained that the area of △ CDE = EF × CD / 2 = 2 √ 2 × 2 / 2 = 2 √ 2. Obviously, the volume of ABCD = the volume of triangular pyramid a-cde + the volume of triangular pyramid b-cde