Thank you, math masters, thank you, math gods

Here you go**!! See for yourself!

a(-1,0), axis of symmetry x=1, known from symmetry b(3,0).So let the quadratic function f(x)=a(x-3)[x-(-1)]....Two-pole type. Substituting point c gives a = root number 3 3, so f(x) = root number 3 3 (x-3) (x+1).

Straight line bc: x - root number 3y = 3Let p(m,n); f(m,q);Bringing in the parabola and the straight line respectively, n = root number 3 3 (m-3) (m+1); q=m root number 3 - root number 3 ; So |pf|=|q-n|= root number 3 3 times m squared + root number 3m (0 the maximum value of the PBC area, because the length of the straight line BC is constant, so the farther P is from BC, the higher it is. When a straight line parallel to BC is tangent to the parabola, the tangent point is at its greatest distance from BC. Let's take the line to x-root, 3y=g

Bringing in the parabola when =0, solve g=21 4. So the distance between two straight lines is 9 16.|bc|=2 times the root number 3.

So the maximum area is 9 times the root number 3 16.

Think of 1 q as a whole, solve a quadratic equation about 1 q or multiply q 2 on the left and right, and finally if there is a root that is 0, just round it off, and the result is 1 2, -1 3 to be adopted.

ad=6 The process is: do be parallel to ad cd to e, angle bec equals angle dThen the angle EBC is equal to 50 degrees, because the angle c is equal to 50, so EB=EC=DC-DE=DC-AB=10-4=6

ad=6.

Crossing point A does AE parallel to BC and DC crosses point E. Then aed= c=50°, in the triangle ade° c=50°, d=80°, so dae=50°, so ad=de=10-4=6

1: What is the price of each bottle of mineral water in the supermarket today?

Price: 1*(1+20%) yuan.

Two: How many bottles of mineral water are sold in the supermarket today?

Sales: 360 bottles.

1. The original price is 1 bottle.

2. 300 bottles were sold.

Well, I'll tell you all about it.

Question 1, [What is the price of each bottle of mineral water in the supermarket today]? First ask question two: [How many bottles of mineral water did the supermarket sell today]?

According to the known condition 3, the retail price is 1+20%=120%;

According to the known condition 1, the [sales volume] is 360 120% = 300 bottles, i.e., the sales volume of mineral water in the supermarket today.

In this way, it is convenient to find the original [retail] price:

First calculate the total retail sales of [original plan]: 360 80%=450 yuan, and then calculate the original planned sales per bottle: 450 300 = yuan.

Let team A complete the task at a speed of x, team B is (5 9)x, and team C is (4 9)x; Now Team A has 10% left, Team B 50%, Team C 60%, Team A sends 2 3 people to help Team C, so Team A's speed becomes (1 3)X, Team C (4 9 + 2 3) X = (10 9)X, Team B remains the same, Team A needs 10% (1 3)X=30% X to complete the remaining 10%, Team C needs 60% (10 9)X=54% X, C takes more time than A, so when Team C completes the task, Team A has completed it, and Team B completes the task is 50% + (5 9）x 54% x=50%+30%=80%。 Choose A

It's B, because the first one is 50 percent of 80 percent, and it becomes more than half of A, so it's B.