How to write the mixed operation of addition and subtraction of rational numbers in the form of omitting the sum of plus signs Examples: (+ 15) + (- 30) - (+ 14) - (- 25) and the rules of solving problems

How to write the mixed operation of addition and subtraction of rational numbers in the form of omitting the sum of plus signs Examples: (+ 15) + (- 30) - (+ 14) - (- 25) and the rules of solving problems

（+15）+（-30）-（+14）-（-25）%A=15-30-14+25%A=-4

Under what circumstances can a mixed operation of addition and subtraction omit brackets and plus signs

When the mixed operation of addition and subtraction is unified into addition operation, bracket and plus sign can be omitted

In the elevator moving upward with acceleration a, there is a spring whose stiffness coefficient is K and mass is ignored. Under the spring, there is an object with mass M. the speed of the object relative to the elevator is zero. When the acceleration of the elevator suddenly becomes zero, the observer in the elevator can see that the maximum speed of the object is? How to calculate? I'm not right. The answer is a √ (M / k)

The mixed operation of rational multiplication and division is carried out in the order of or after

The mixed operation of multiplication and division of rational numbers is carried out from left to right or from left to right after multiplication

I want to know P = MW, W is the angular velocity, M is the torque. Is this formula a definition or how to get it,

Power = force * distance / unit time = force * speed, I don't need this
So power = linear velocity * force = angular velocity * radius * force = angular velocity * torque
over!

It is known that {an} is an arithmetic sequence whose first term is - 16 and the tolerance is not 0. The sum of the first n terms is Sn, and A1, A5 and A4 are equal ratio sequence. The tolerance D of {an} can be obtained

It is known that {an} is an arithmetic sequence whose first term is - 16 and tolerance is not 0,
The sum of the first n terms is Sn, and A1, A5 and A4 are in equal proportion sequence. The tolerance D of {an} can be obtained
set up
a1=-16
a5=-16+4d
a4=-16+3d
So,
a5²=a1*a4
Namely
(-16+4d)²=(-16)*(-16+3d)
=16²-128d+16d²=16²-48d
So,
16d²=80d
So, d = 5
Hope to adopt~~~

A trolleybus runs in a straight line from a stationary and uniformly accelerating ground with an acceleration of 2.0 M / S2. (1) calculate the speed of the trolleybus after 10 s; (2) if the trolleybus starts to drive at a speed of 10 m / s with the same acceleration, how much is the parking space moved after 8 s?

(1) After 10s, the speed of tram is v = at = 2 × 10m / S = 20m / S. (2) the time to reduce the vehicle speed to zero is t0 = 0 − v0a = 0 − 10 − 2S = 5S ＜ 8s, then the displacement within 8s is equal to the displacement within 5S, X = v02t0 = 102 × 5m = 25m

Xiaojun's walking distance is 14 more than Xiaohong's, but Xiaohong's walking time is 110 more than Xiaojun's______ ．

The distance ratio of Xiaojun and Xiaohong is: (1 + 14): 1 = 54:1 = 5:4; the time ratio of Xiaojun and Xiaohong is: 1: (1 + 110) = 1:1110 = 10:11; then the speed ratio of Xiaojun and Xiaohong is: (5 ﹣ 10): (4 ﹣ 11) = 510:411 = 11:8

English exercises (grade one)
There ______ (go) the bell.
My uncle invited us to visit some interesting places in Shanghai
My uncle invited us to visit _____ _____ _____ _____ in Shanghai.

This is an inverted sentence
Some places of interest
Please take my answer. I'm the first to answer

There are three points a, B and C on the number axis. They can move left and right along the number axis. Please answer. If a, B and C move, they will get three mutually incompatible points
If three points a, B and C move to get three mutually unequal rational numbers, they can be expressed in the form of 1, a, a + B, or 0, B, B divided by A. try to find the value of a and B

1,a,a+b
0,b,b/a
Because a ≠ 0, a + B = 0
If B = 1, then a = - 1 satisfies the problem
If B / a = 1, then
If B = A and a + B = 0, then a = b = 0
therefore
a=-1 b=1