[profit, profit margin, cost, purchase price, selling price, etc.]

[profit, profit margin, cost, purchase price, selling price, etc.]

Profit: selling price purchase price
Profit margin: profit / purchase price

The relationship between selling price, purchase price and profit margin

Profit = selling price purchase price
Profit margin = (selling price purchase price) × selling price
Cost profit rate = profit △ purchase price × 100%
Sales profit margin = profit △ selling price × 100%

Given that the square of (2x-1) is equal to the square of AX + BX + C, find the value of a + B + C. because when x = 1, the square of AX + BX + C = a + B + C, so a + B + C = (2 * 1-1) square = 1 (1) can you find the value of A-B + C in a similar way? (2) try to find the value of formula a + C, and then find the value of 4A + B + 4C

Yes
(1)
Let x = - 1
(2x-1)²=[2(-1)-1]²=a(-1)²+b(-1)+c=a-b+c=(-3)²=9
a-b+c=9
(2)
a+b+c=1 (1)
a-b+c=9 (2)
(1)+(2)
2(a+c)=10
a+c=5
(3)
4a+b+4c
=3(a+c)+(a+b+c)
=3×5+1
=16

The area of a triangle is 20 square centimeters, the bottom is 2 centimeters, and how high is it?

Height of triangle = area * 2 / bottom
20 * 2 / 4 = 10 cm

Given that point P is a moving point on the parabola y2 = 2x, the projection of point P on the Y axis is m, and point a (72,4), then the minimum value of | PA | + | PM | is ()
A. 5B. 92C. 4D. AD

Then | PF | = | pH | PM | = | pH | - 12 = | PA | - 12 | PM | + | PA | = | PF | + | PA | - 12, we can only find the minimum value of | PF | + | PA |

（9.8-1.8x）×7=18.22.6x=51.6-3.4x3（4x-2）-2（3x+3）=9-8x20+4x=6x-245（x-1）=x+13（3x-2）=10-0.5（x-3.5）0.4（x-0.2）+1.5=0.7x-0.38（0.6x+420）÷（x+20）=335（2-x）+15（6-5x）=22x+7+21（4-3x）

（1）（9.8-1.8x）×7=18.2，  （9.8-1.8x）×7÷7=18.2÷7，            9.8-1.8x=2.6，       9.8-1.8x+1.8x=2.6+1.8x，            2.6+1.8x=9.8，        2.6+1.8x-2.6=9.8-2.6，                1.8x=7.2，           1.8x÷1.8=7.2÷1.8，                   x=4；（2）2.6x=51.6-3.4x，2.6x+3.4x=51.6-3.4x+3.4x，       6x=51.6，    6x÷6=51.6÷6，        x=8.6；（3）3（4x-2）-2（3x+3）=9-8x，                  6x-12=9-8x，               6x-12+8x=9-8x+8x，                 14x-12=9，              14x-12+12=9+12，                     14x=21，                14x÷14=21÷14，                       x=1.5；（4）20+4x=6x-24，  20+4x-4x=6x-24-4x，     2x-24=20，  2x-24+24=20+24，        2x=44，     2x÷2=44÷2，         x=22；（5）5（x-1）=x+1，        5x-5=x+1，       5x-5-x=x+1-x，        4x-5=1，      4x-5+5=1+5，          4x=6，       4x÷4=6÷4，           x=1.5；（6）3（3x-2）=10-0.5（x-3.5），         9x-6=11.75-0.5x，    9x-6+0.5x=11.75-0.5x+0.5x，       9.5x-6=11.75，     9.5x-6+6=11.75+6，         9.5x=17.75，    9.5x÷9.5=17.75÷9.5，            x=4738；（7）0.4（x-0.2）+1.5=0.7x-0.38，           0.4x+1.42=0.7x-0.38，      0.4x+1.42-0.4x=0.7x-0.38-0.4x，            0.3x-0.38=1.42，      0.3x-0.38+0.38=1.42+0.38，                0.3x=1.8，           0.3x÷0.3=1.8÷0.3，                    x=6；（8）（0.6x+420）÷（x+20）=3，（0.6x+420）÷（x+20）×（x+20）=3×（x+20），                      3（x+20）=0.6x+420，                           3x+60=0.6x+420，                     3x+60-0.6x=0.6x+420-0.6x，                         2.4x+60=420，                     2.4x+60-60=420-60，                            2.4x=360，                      2.4x÷2.4=360÷2.4，                              x=150；（9）35（2-x）+15（6-5x）=22x+7+21（4-3x），                160-110x=91-41x，           160-110x+110x=91-41x+110x，                   69x+91=160，               69x+91-91=160-91，                     69x=69，                  69x÷69=69÷69，                       x=1．

Known circle C: (x-1) ^ 2 + (Y-2) ^ 2 = 2, point P is (2, - 1), through point P do tangent of circle C, tangent point a, B（
1) The equation for finding the straight line PA and Pb (2) finding the length of tangent PA (3) finding the straight line equation through two points a and B (4) finding the chord length | ab|

1) Let the distance between the center of the circle and the straight line be equal to R,
2) The center of the circle is C, T. calculate PA, R, PC with Pythagorean theorem
3) It's faster to use geometry

It is known that P is a moving point on the parabola y ^ 2 = 2x. The tangent of the circle (x-3) ^ 2 + y ^ 2 = 1 is made through P. the tangent points are m and N respectively,
Then the minimum value of / Mn / is__________ The detailed process needs to be explained

Let P (2a) &# 178;, 2a) be the center C (3,0) of the circle C: (x-3) &# 178; + Y & # 178; = 1, and R = 1. Let PC and Mn intersect at point h, it is easy to know that ⊿ MCH ≛ PCM  MH ∶ PM = MC ∶ PC  MH = PM / PC and PM & # 178; = PC & # 178; - 1  Mn = 2 √ [1 - (1 / PC & # 178;)]. The problem can be reduced to the problem of finding PC & # 178

As shown in the figure: in rectangular paper ABCD, ad = 4cm, ab = 10cm, fold as shown in the figure, so that point B and point d coincide. If the crease is EF, the de length is ()
A. 4.8B. 5C. 5.8D. 6

If A1 = m + 1, A2 = 1 / 1-a1, A3 = 1 / 1-a2, A4 = 1 / 1-a3 Then the value of a2013 is________ (expressed by an algebraic expression with m)

a1=m+1,a2=1/(1-a1)=1/(1-m-1)=-1/m
a3=1/(1-a2)=1/(1+1/m)=m/(1+m)
a4=1/(1-a3)=1/[1- m/(1+m)]=1/[1/(1+m)]=1+m
So we can see that the number of this column is arranged in the order of M + 1, - 1 / m, M / (1 + m), circularly and repeatedly
Because 2013 △ 3 = 671, a2013 = m / (1 + m)