7th Grade Math Winter Vacation Homework Question Urgent! ）

Solution: purchase price: original: 1 now: 1-8%.

Sales price: Original: x Now: x

x-92%）/92%-(x-1)=10%

x = original profit percentage: (

92% here is 1-8% get, oh yes.

The original shelf is $ x, and the selling price is $ y.

y-(1-8%)x]/(1-8%)x-(y-x)/x=10%y/x=

Profit = (y-x) x=y x-1=

Let the original purchase price be x and the selling price be y

Based on a 10% increase in profit The relation can be found: (y-x)*(1+ = Solve the equation to get y=

So the original profit is: x

The original profit x is: (1-x)*8%=10%.

Conclusion: x=Problem with the question.

1.Yellow ball, yellow area.

2.Yellow burnt eggplant cracked bulb, red area.

3.Yellow ball, green area.

4---9 and so on, you should be closed, you should understand.

As for the charts, I suggest that you draw the net charts horizontally and vertically to get the color of the ball.

1.Analysis: (1) The essence is to find the quadrants of x,y signs. A: x>0, and y<0 is in the fourth quadrant;

Another: x<0 and y>0, which is in the second quadrant.

Therefore, it is the second or fourth quadrant.

2) is the first and third quadrants.

2.(1) The point on the x-axis, the ordinate y=0, so m-1=0 knows the point on the m=1y-axis, and the abscissa x=0, so n+2=0 knows that n=-2(2)a,b,c,d four points in the line y=-xIf the four points cannot be obtained by observation in the line y=-x, let y=kx+b, try to bring the above four points in, and find k and b

In this problem, k=-1, b=0

1. (1) point p, one positive pair, so in the second or fourth quadrant, (2) point p is on the bisector of one or three quadrants, i.e., y=x

2. (1) The point ordinate of the x-axis is 0, so the abscissa of the point of the m=1y-axis is 0, so n=-2

2) The four points are all on a straight line, because their horizontal and vertical coordinates are all opposites, and therefore they are all on the straight line y=-x, i.e., the bisector of the two quadrants.

1 (1)xy must be one plus and one minus, obviously in two or four quadrants. (2) is a straight line that passes through one or three quadrants. 2(1)m=1 n=-2 (respectively so that m-1=0 n+2=0)(2) are above the straight line y=-x.

When he walked to the sixth pole, he walked five intervals, and when he used, the time to walk one interval was. 32 seconds.

Then when he reached the tenth pole, he walked 9 intervals, and the time taken was: 88 seconds c

From 1 to 6, there are 5 intervals in between, each interval =

From 1 to 10, there are 9 intervals in between, and a total of =

Answer: c

From the first root to the sixth root at a constant rate. But the interval distance is five. That is, from the sixth root to the tenth root, the interval distance is 4.;Then there is 4*, then the total time.

d should be so spider ant astronomy and geography science reason, anyway do it.!

There are nine segments of ten rods. Six rods have five segments. ，

When you go to the 6th root, you have to go 5 sections, and you need to go to 10 roots, and you need to go 9 steps when you go to the 10th root, which is to choose C

x+y=4,|x|+|y|=7, we can see that one of x and y is positive and the other is negative.

The solution is that the positive number is a negative number.

The value of x-y is 7 or -7

If x>0, then x+y=4, -x+y=7, and the solution is x=,y=, then x-y=-7

If y>0, then x+y=4, x-y=7, and the solution is y=, x=, then x-y=7

First of all, x,y must be a plus and a minus...

Since it's one plus and one minus.

Then |x|+|y|=x-y or ,|x|+|y|=y-x means x-y=7 or -7

From the first two equations, we can see that one of the xy is less than zero, so (x-y) = x +y -2xy, but xy < 0 so (x-y) =x +y +2|xy|，|x|+|y|）²=x²+y²+2|xy|=49 so x-y=+7

It can be seen that x and y are different signs, so the value of x-y is 7 or -7

X and Y must have one positive and one negative.

And they are -3 2 and 11 2, respectively

So the value of x-y is 7