The perimeter of triangle ABC is 20, ac-ab = 2, and the value range of AC is obtained

The perimeter of triangle ABC is 20, ac-ab = 2, and the value range of AC is obtained

AB+BC+CA=20
AC-AB=2,AB=AC-2
1.AC+AB>BC=20-AB-AC
AC+AC-2>10
AC>6
2.AC-AB

A + B = 3 (both a and B are natural numbers), and the greatest common divisor of a and B is______ The least common multiple is______ ．

Because a + B = 3, 3 is odd, it can be seen that a and B are 1, 2, 1 and 2 are coprime numbers, so their greatest common factor is 1 and the least common multiple is 2

K means (Tan value) K1 = K2, B1 ≠ B2 is an example of sufficient and unnecessary condition for two lines to be parallel

Two vertical lines

Plural number of potato

potatoes

Parabola and y = a (x-3) ² + 5 have the same image shape, and the analytic formula of y-axis symmetry and y-axis intersection (0,14) is obtained

On Y-axis symmetry
So y = a (- x-3) ² + 5
y=a(x+3)²+5
x=0
y=9a+5=14
a=1
So y = x & # 178; + 6x + 14

If | a + 2 | + | B-3 | + | C-4 | = 0, then the value of formula a + 2B + 3C is______ ．

According to the meaning of the question, a + 2 = 0, B-3 = 0, C-4 = 0, the solution is a = - 2, B = 3, C = 4, so a + 2B + 3C = - 2 + 2 × 3 + 3 × 4 = - 2 + 6 + 12 = - 2 + 18 = - 16

Why does the parametric equation x = tank, y = Cott and xy = 1 represent the same curve? Can tank get 0? Isn't xy = 1 x not equal to 0? What's the matter?

x=tant
y=cott
Then t ≠ K π + π / 2 or t ≠ π K
Otherwise, x, y have no meaning

Square of (x + y) times (X-Y) - (X-Y) times (square of X + square of Y)

=(x-y)[(x+y)²-(x²+y²)]
=(x-y)(x²+2xy+y²-x²-y²)
=2xy(x-y)

In the plane rectangular coordinate system, the coordinates of a, B and C are (0,0), (4,0,) (- 3, - 2) respectively. Draw parallelogram with a, B and C as the vertex,
Then the fourth vertex cannot be in the second vertex________ Quadrant
fast

In the plane rectangular coordinate system, the coordinates of three points a, B and C are (0,0), (4,0,) (- 3, - 2) draw a parallelogram with three points a, B and C as the vertex, then the fourth vertex cannot be in the second quadrant

X + 1 of x = 3x + 3 of 2x + 1

A
x/(x+1)=(2x+1)[3(x+1)]
Multiply both sides by 3 (x + 1)
3x=2x+1
x=1
It is proved that x = 1 is the solution of the original equation