8th Grade Math Solving It s better to have an analytical process Thank you

2, III. 3, b= -3, k=3, 2, x>24, four 360

6. (1) A: y=x+1500 B: y=3) x=800, YA=2300>YB=2000, select B plant.

This is the application of the formula for the interior angles of regular polygons.

The formula for the internal angles of a regular n-sided is 180(n-2) n, so each inner angle of a regular pentagonal = (5-2) 180° 5=108° understood? This step is actually to connect the acute angles of the brother of the pentagram to form a regular pentagon, find the inner angle of the regular pentagon, and then subtract 60 degrees from the inner angle of the regular pentagon to be the degree of the inner angle of the pentagram.

You can see it when you draw it on the diagram.

The formula for the inner angle of a regular n-sided is 180(n-2) n

So each inside angle of a regular pentagon = (5-2) 180° 5 = 108°

Draw another picture, and it's OK.

Can you put on a picture? I don't know what it looks like if I don't look at the picture.

Do the midpoint of AB H, BP=3 4AB, so point P is the midpoint of Ah, the intersection point of the midline G is the center of gravity, PG=PC3.

In the figure below, there are two cases, m1 and m2, and the result can be obtained by using similar triangles (two equal angles).

If there's an easier way, ask for advice! Thank you so much! I wish the subject more and more excellent results

Be sure to listen well in class.

1.The distance from p(-5,-6) to the x-axis is (|.)y|=6), the distance to the y-axis is (|x|=5), the distance to the origin is (under the root number (5 2 + 6 2) = root number 61).

2.The function y=-2 3x+1 does not pass through quadrant (3).As shown in the figure, the line l is an image of the function y=kx+b, then b= (-3), k= (3 2), and y>0 when x (>2).

4.If the sum of the inner and outer angles of a polygon is equal, then the polygon is a (quadrilateral) polygon, and the sum of its internal angles is (360) degrees.

5.Calculate (6-2-15)*3-6-1-2=(-6-5)6.(1) A y=x+1500

B y=2) omitted.

3) A=800+1500=2300

B = , so B is cost-effective.

The format is best this way. Question 1: Question 2: Question 3: Answer 1: Answer 2: Answer (2) b is the intersection of the primary function ab and the positive half axis of the x-axis, and ba = bo, find the analysis of the primary function.

m>1, x 2-2x+m=(x-1) 2+m-1>0, impossible = 0, then the above equation is interesting!

To make the equation meaningful no matter what value x takes, then x 2-2x + m = 0 has no solution, i.e., b -4ac<0, i.e., 4-4m<0

i.e. m>1

It only makes sense for an equation to have a solution, so that m 1 can be obtainedSecond, x -2x+m≠ 0, when m=1, x -2x+m=0, has no meaning d

It always makes sense to choose b as a fraction, which means that the denominator cannot be zero. When the value of x is 0, the denominator = m, so m cannot be 0, and the answer options c and d are excluded.

However, when the value of m is 1, the denominator = x 2-2x+1, and when the value of x is 1, the denominator is 0, which is not feasible, so m cannot be equal to 1, and the answer is b