Primary school simple calculation (1) 1 × 27 of 5 + 3 × 41 of 5 (2) 9 + 99 + 999 + 9999 (3) 135 △ 12.5 (4) 1325-998 (5) 34 × 2 and 13 of 34 Please master (1) 1 / 5 × 27 + 3 / 5 × 41 （2）9+99+999+9999 (3)135÷12.5 （4）1325-998 (5) 34 × 2 and 13 / 34 Answer as many questions as you can

Primary school simple calculation (1) 1 × 27 of 5 + 3 × 41 of 5 (2) 9 + 99 + 999 + 9999 (3) 135 △ 12.5 (4) 1325-998 (5) 34 × 2 and 13 of 34 Please master (1) 1 / 5 × 27 + 3 / 5 × 41 （2）9+99+999+9999 (3)135÷12.5 （4）1325-998 (5) 34 × 2 and 13 / 34 Answer as many questions as you can

(1) Become 3 / 5 times 9 + 3 / 5 times 41 = 3 / 5 times (9 + 41) = 10
（2）=10+100+1000+10000-4
(5) 34 times 81 out of 34 = 81

Simple operation of 98 + 999 + 9996 + 99997 + 10

98+999+9996+99997+10
=100-2+1000-1+10000-4+100000-3+10
=111100

Know straight line equation and circle equation to find tangent
Y = x-3 is tangent to 2x ^ 2 + 2Y ^ 2-9 = 0 to find the coordinates of the tangent point. By the way, what is the leading line from the point to the circle~

Directly substituting y = x-3 into the circular equation, we get 2x ^ 2 + 2 (x-3) ^ 2-9 = 0
4x²-12x+9=0
x=3/2,y=-3/2
Tangent point (3 / 2, - 3 / 2)
The leading line from a point to a circle is the connecting line between a point and any point in the circle

Party A and Party B transport a lot of goods. Party A transports more than 90 tons, 7 / 15 of the total. Party B transports more than 30% of Party A's. how many tons does party a transport,
Urgent···········

Let the total number of solutions be X
7 / 15 x + 90 + 0.3 (7 / 15 x + 90) + 1 = x

If the root of equation (2a + 5) / 3 = (5x + 1) / 4 is negative, then the value range of a is -- ()

∵（2a+5）/3=（5x+1）/4
∴4（2a+5)=3(5x+1)
∴x=(8a+17)/15＜0
∴a＜-17/8

A pile of yellow sand has carried away a quarter of it, and a fifth of it. At this time, there are 225 cubic meters of yellow sand left. How much yellow sand has been carried away?
Now! Better explain why!

There are x cubic meters of yellow sand
x-1/4x-(x-1/4x*1/5)=225
X = 375 is the total amount of yellow sand
375 minus 225 equals 150, which is the amount of yellow sand transported

The linear equation of y = 2x with respect to X-axis symmetry is______ ．

From the line y = 2x, we can know that: the slope of the line is 2, the intercept on the Y axis is 0 ∵ the line y = 2x is symmetric about the X axis ∵ the slope of the symmetric line is - 2, the intercept is 0, so the equation of the line y = 2X about the X axis symmetry is y = - 2x, so the answer is: y = - 2x

There are 48 people in the first workshop and 56 people in the second workshop of the electric appliance factory. After the same number of people has been cut in the two workshops, the number of people in the second workshop is two-thirds more than that in the first workshop, two cars
How many workers will be cut in between?

There are x people in total
56-1\2x=（48-1\2x）*（1+2\10）
x=16

Given x square + 2Y square - 2XY + 4xy + 4 = 0, find [(XY + 2) (XY-2) - 2x square, y square + 4]

Solution
X & # 178; + 2Y & # 178; - 2XY + 4Y + 4 = 0
(x²-2xy+y²)+(y²+4y+4)=0
(x-y)²+(y+2)²=0
∴x-y=0,y+2=0
∴x=-2,y=-2
∴[(xy+2)(xy-2)-2x²y²+4]
=(x²y²-4-2x²y²+4)
=-x²y²
=-4×4
=-16

If 4 / 7 of the girls in a class is equal to 2 / 3 of the boys, then the number of boys () the number of girls
Formula Plus answer, a less than b greater than C equal to

Let X be the person with a score between 3 and 7, and the average score is y-x0d
The average score of those who get at least 3 points is 6 points
That is, XY 8 * 3 9 * 3 10 * 1 = 6 * (x 3 1) / x0d
xy=6x-19\x0d
\x0d
The average score of those who score less than 8 is 3
That is, XY 2 * 4 1 * 5 0 * 7 = 3 * (x 4 5 7) / x0d
xy=3x 35\x0d
\x0d
So 6x-19 = xy = 3x 35
3x=54\x0d
x=18\x0d
\x0d
So there are 13 3 18 4 5 7 = 41