Grade 9 Math Answer Questions To Write Process Thank you

What is the problem? There is no question of how to answer.

There is Vedic theorem: x1 + x1 = 2m x1 x2 = 3m δ = 4m -12m 0

x1-x2) = (x1+x2) -4x1x2=4m -12m=16 m=4 or m=-1

When m=4, x -2mx+3m=0, two roots, x1=2, x2=6x-2mx+6m-9=0, two roots are x3=3, and x4=5 are established between the two roots.

When m=-1, x -2mx+3m=0, two roots, x1=4, x2=-1x-2mx+6m-9=0, two roots are x3=-5, and x4=3 is obviously not true.

So m=4

x1+x2=2m

x1x2=3m

x1+x2）²-4x1x2=（x1-x2）²4m²-12m=16

m= 4 ,m=-1

Substituting the second equation into each to get the root.

Excluding -1 yields m = 4

Untie; Since the two real roots of the equation x -2mx + 3m = 0 are x1 and x2, according to Veda's theorem, we get.

x1+x2=2m

x1*x2=3m

And because (x1-x2) = 16, there is.

x1-x2）²=x1²-2*x1*x2+x2²

x1²+2*x1*x2+x2²-4*x1*x2

x1+x2）²-4*x1*x2

2m）²-4*3m

4m²-12m=16

m²-3m-4=0

m-4）*（m+1）=0

Get m=4 or m=-1

When m=4, x -2mx+3m=x -8x+12=(x-2)*(x-6)=0 gives x1=2 , x2=6

x -2mx+6m-9=x -8x+24-9=x -8x+15=(x-3)*(x-5)=0 gives x1=3 , x2=5 The two real roots are between 2 and 6.

When m= -1.

x -2mx+3m=x +2x-3=(x+3)*(x-1)=0 gives x1=-3 and x2=1

x -2mx+6m-9=x +2x-6-9=x +2x-15=(x+5)*(x-3)=0 gives x1=-5 , x2=3 The roots of the two real numbers are not between -5 and 3.

In summary, m=4

Ah, it's finally finished, and it turns out that computers are not as fast as handwriting!

When the two images intersect at the point p, the function value is the same, so 2x-6=-x+3, the solution is x=3, and x=3 is substituted into y=-x+3 to get y=0, so the coordinates of p point are (3,0).

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Hello. It takes a little time to write and solve problems. You've been waiting for a long time The above is the process of solving the first problem for you

Hello. The above is the process of solving the second question provided for you. When the sales unit price is 20 yuan, the profit is the largest, and the maximum profit is 1000 yuan.

(1) y=30+x(2)

2)p=(30+x)(1000-3x)=-3x2+910x+30000

3)w=-3x2+910x+30000-10000×30-310x=-3(x-100)2+30000

x<160 so after 100 days of storage** can get the maximum profit, the maximum profit is 30,000 yuan.

(1) y=x+30

2) p = (1000 --3x) (x + 30) = 3x squared + 910x + 30000

3) w = p --1000 times 30 --310x = -3x squared + 600x = -3 (x squared --200x + 10000) + 30000 = -3 (x --100) squared + 3000

Therefore, Manager Li will store this batch of wild mushrooms for 100 days.

(1) The profit of each loaf is (yuan, and the number of loaves sold is 160-20 (

2) y=(3)y=-200x 2+400x-150=-200(x-1) 2+50, when the bread price is 1 yuan, the store has the largest daily sales profit, which is 50 yuan.

(1) Gain of each: x—

The number is 160-20 (x-

2)y=(160—20（x—

3) Finishing (2) to get y=-200(x-1) 2+50 Therefore, when each loaf is 1 yuan, the sales profit is the largest, and the maximum is 50 yuan.

(1) f(x)=-x 2+2(m-1)x+m+2 According to the known f(0)>0, m+2>0 to obtain m>-2

2).Let a be (a,0)a<0 then b is (-5a,0) by Vedic theorem 2 (m-1) = -4a-(m+2)=-5a^2.The solution is a=-1(a=3 5>0 rounded).

So there is m=3

Therefore, the parabolic equation is y=-x 2+4x+5

The question is simple. It's just that those symbols are too difficult to play.,What a root number.,Absolute value.,2 power.。 The first problem is to let the range of m values when the equation has two different solutions, so that the root finding formula is greater than 0.

In the second problem, let the ratio of the absolute values of the two roots found by the root finding formula be 1:5 and 5:1 respectively, and solve m

According to the points c, d are divided into semicircles, so the cd line is parallel to ab, so s cdb s cdo because the two are equal and the same height.

And the arc part of the shaded part is common to these six triangles, so: the area of the shaded part is one-third of the area of the semicircle, r 6 2 3 square centimeters

where the area of the circle r 4

The area of the semicircle is r 2 2

The shaded area is equivalent to the arc db area + triangle dob area s triangle dob = 2 * 3 2 = 3cm 2s arc db = (s semicircle ab-3 * s triangle dob) 3 = (2 -3 3) 3cm 2

s shadow = 2 3