1+2+3+4+5+6+7+8+9+10*90

1+2+3+4+5+6+7+8+9+10*90

four thousand and ninety-five

1+2-3-3+5+6-7-8+9+10~+1990
Simple and convenient operation

The original question should be as follows
1+2-3-4+5+6-7-8.+1990
It can be reduced to 1 + 2 + (- 3-4 + 5 + 6) + (- 7-8 + 9 + 10) + (- 1987-1988 + 1989 + 1990)
=3+4*497
=1991

-1-2+3+4-5-6+7+8-9-10+11+12-13-14...+2011+2012-2013

-2009

In the number which is not only a multiple of 16 but also a factor of 12, the smallest one is ()
reason

Is to find the least common multiple of 16 and 12
The least common multiple of 16 and 12 is 48
The smallest one is (48)

It is a system of linear equations with three variables: x + y + Z = 0,4x + 2Y + Z = 0, z = 2;

X+Y+2=0
4X+2Y+2=0
We get 2x-2 = 0
X=1 Y=-3 Z=2

What does sign language applause mean

Given the point m (3,5), find a point P and a point Q on the line L: x-2y + 2 = 0 and the y-axis to minimize the perimeter of △ MPQ

From point m (3,5) and line L, the symmetric point M1 (5,1) of point m with respect to l can be obtained. It is also easy to obtain the symmetric point M2 (- 3,5) of point m with respect to y-axis. According to M1 and M2, the equation of line m1m2 can be obtained as x + 2y-7 = 0. The intersection point P (52,94) can be obtained. Let x = 0, the intersection point Q (0,72) of m1m2 and y-axis can be obtained That is what we want

The difference between a and B is 198. If you move the decimal point of a to the left by 2 places, the number of a and B will be the same. What are the two numbers

It says that if you move the decimal point of number a to 2 places to the left, number a and number B will be the same, then number a is 100 times of number B, and the ratio of number a to number B is 100:1. Because the difference between number a and number B is 198, then the difference between the number a and number B is 198, so use 100-1 = 99198 / 99 = 2 to explain each

If the solution set of linear inequality system x > 3 and x > A is x > 3, can you find the value range of a?

Of course, because x > 3, x > A, by the nature of inequality: the same big take the big number, and because the solution set is x > 3, so the value range of a is x less than or equal to 3, study hard, inequality, this is very important in the future study

There are three classes planting trees in Grade 6 of experimental primary school. The proportion of trees planted in class 1 to that in class 3 is 3:4, and that in class 2 is 24 less than that in class 3,
How many trees are planted in the three classes?

24 / (4-3) x (4 + 3) = 168 trees were planted