3 (x + 2) (X-2) = 0 is solved by factorization

3 (x + 2) (X-2) = 0 is solved by factorization

5x (x-3) - (x-3) (x + 1) = 0 is solved by factorization?

(x-3) (5x-x-1) = 0 (x-3) (4x-1) = 0, so x = 3 or x = 1 / 4

What is the diameter of a hair
The common answer is accurate to 0.1 mm

According to different people, the thickness is different, the general thickness is 7 wires = 0.07mm ≈ 0.1mm

A and B planes fly from two airports 750 km apart at the same time and arrive at the same Midway Airport for half an hour. If the speed of a plane is 1.5 times that of B plane, what is the speed of B plane?

750 △ 0.5 × 11.5 + 1 = 1500 × 25 = 600 km a: the speed of B plane is 600 km per hour

There is a column of numbers 1.1.2.4.7.13.24.44.81,
Is the 100th number odd or even

According to odd plus odd equals even,
Even number plus even number equals even number,
Odd plus even equals odd,
It can be concluded that the parity ratio of the sequence is periodic
It can be found that every four cycles are odd even cycles
100 / 4 = 25 + 0
The parity of the 100th digit is the same as that of the 4th digit
So the hundredth number is even
I hope my answer will help you!

3A B Cube - 6 a square B + 3 a cube

3A B Cube - 6 a square B + 3 a cubic B
=3AB (b square - 2Ab + a square)
=3AB (B-A) square

As shown in the figure, in △ ABC, ∠ ACB = 90 °, point E is the midpoint of AB, connecting CE, passing through point e to make ed ⊥ BC at point D, taking a point F on the extension line of De to make AF = ce.verification: quadrilateral ACEF is a parallelogram

It is proved that: point E is the midpoint of AB, AE = EB, ACB = 90 degree, CE = AE = EB, AF = CE, AF = AE, AF = AE, EB = EC, ed ⊥ BC, 1 = 2 (three lines in one), 2 = 3, 1 = F, CE ∥ AF and ACEF are parallelogram

There are 80 red balls, 70 blue balls, 60 yellow balls and 50 white balls in the bag. They are all the same in size and quality. How many balls should we take to make sure that we can get 10 pairs of balls (two balls of the same color are a pair)?
Explain in detail

At least = 10 × 2 + 3 = 23

3000 square decimeters=______ Square meter, 800 square decimeter=______ Square centimeter

(1) 3000 square decimeters = 30 square meters; (2) 800 square decimeters = 80000 square centimeters

1、 In the following equation, "Ying" represents a five digit number, "new" and "year" represent two different four digit numbers
1 1 1 1
---- + ---- + ---- = ----
New year 2008
What number does "Ying" stand for?
2、 It is known that "Shu", "Xue", "Wang" and "Guo" represent four continuous natural numbers from small to large
1 1 1 1 19
Known: --- + --- + --- + --- = 1----
The kingdom of mathematics 20
1 1 1 1 （）
So: --- + --- + --- + --- = 1----
The kingdom of Mathematics ()
It's tilted to the left. When you look at it, you look to the right
The title is wrong
1 1 1 1 （）
Then: --- X ------
The kingdom of Mathematics ()

1. Ying = 2008 × 6 = 12048
New = 2008 × 3 = 6024
Year = 2008 × 2 = 4016
2. The original formula = 1 / 3 + 1 / 4 + 1 / 5 + 1 / 6 = 57 / 60 = 19 / 20