Given that the value of the algebraic formula 12x - (X-2) / 3 is 0, find the algebraic formula (3x-1) / 4 + (2x + 1) / 3

Given that the value of the algebraic formula 12x - (X-2) / 3 is 0, find the algebraic formula (3x-1) / 4 + (2x + 1) / 3

Turn the first formula into a general form
That is 35 / 3x + 2 / 3 = 0
Replace (3x-1) / 4 + (2x + 1) / 3 with 7 / 6x + 1 / 12
Divide the left and right sides of the first equality sign by 30
7 / 6x-1 / 15 = 0, that is, 7 / 6x = 1 / 15
If it is brought in, the formula equals 1 / 15 + 1 / 12 equals 3 / 20
So (3x-1) / 4 + (2x + 1) / 3 = 3 / 20

You have a large square cake with a side length of 30 cm. There are four guests in your family. Can you divide the cake into five equal pieces? How many ways do you have? If the side of the cake is made of chocolate, you must make sure that each piece of cake contains the same length of chocolate side when cutting. Can you do it? Can you tell the math behind it?
No wonder I, the title is like this
Think of it as a cube

As shown in the figure, O is the intersection of the diagonal lines of the square, so the height of the triangles in the figure is equal, and set it as X. the area of △ DOH, △ dog, quadrilateral ahoe, oebf and ogcf is 12x. The edge of the chocolate is 24cm

The population of a town has increased by 1200, and then the new population has decreased by 10%. Now the number of people in the town is 32 less than that before the increase of 1200. How many people was the original population?

Set the original x people
(x+1200)(1-10%)=x-32
x=11120

Given that the lengths of two sides of a right triangle are exactly the two roots of the equation 2x square minus 8x plus 7 equal to zero, then the length of the hypotenuse of the right triangle is?

2x*x-8x+7=0
x1+x2=4
x1x2+7/2
x1x1+x2x2=(x1+x2)(x1+x2)-2x1x2
=16-7=9
√(x1x1+x2x2)=3

As shown in the figure, in the quadrilateral ABCD, BA ⊥ Da BC ⊥ DC be bisection ﹥ ABC DF bisection ﹥ ADC verify be ∥ DF

The sum of internal angles of parallelogram is 360 degrees, and angles a and C are 90 degrees, so angles B and D complement each other, that is, angle B + angle d = 180 degrees, be bisecting angle B, DF bisecting angle D can get angle Abe + angle ADF = 90 degrees, and in right triangle Abe, angle Abe + angle AEB = 90 degrees, so angle AEB = angle ADF, and the same angle is be parallel DF

X3-3X2+9X+27
X3-3x2 + 9x + 27 factorization of X3 x to the third power and X2 x to the second power

First guess the answer is - 3, then set (x + 3) (AX & # 178; + BX + C) and remove it. The front coefficients are the same, and then remove a, B, C

1. If 25 × □ / 3 × 15 + 5 = 2005, then □ = (), 2.1-2 + 3-4 + 5-6 +... + 1991-1992 + 1993 =（

Number one: just count backwards
The second: 1-2 + 3-4 + 5-6 +... + 1991-1992 + 1993 = (1-2) + (3-4) + (5-6) +... + (1991-1992) + 1993 = 1992 / 2 * (- 1) + 1993 = 997
(1-2) + (3-4) + (5-6) +... + (1991-1992) this, you see, the first is 1 to 1991, a total of (1 + 1991) / 2 odd numbers, so there are so many - 1

Let the left and right focus of the ellipse x ^ 2 / A ^ 2 + y ^ 2 / b ^ 2 = 1 (a > b > 0) be F1 and F2 respectively, a is a point on the ellipse, af2 ⊥ F1F2
If B = 1, let Q1 and Q2 be the two moving points oq1 ⊥ oq2 on the ellipse, make the perpendicular od of the straight line q1q2 through the origin o, and d be the perpendicular foot, and solve the equation of D

2007 college entrance examination mathematics test Tianjin (Science), question 22

The product of three prime numbers is 78. What are the three prime numbers?

78=2*3*13
The three prime numbers are 2, 3, 13

a> 0, b > 0, and ab + A + 2B = 30, find the minimum value of y = 1 / ab

A + 2B > = 2 radical (2Ab)
30 AB = a + 2B > = 2 radical (2Ab)
Let t = radical (2Ab) > 0
30-(t²/2)>=2t
t²+4t-60