50% of a number is 1.8 more than 13. Find the number

50% of a number is 1.8 more than 13. Find the number

Let this number be X50% x-13x = 1.8 & nbsp; & nbsp; & nbsp; 16x = 1.8 & nbsp; 16x △ 16 = 1.8 △ 16 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 10.8; a: this number is 10.8

50% of a number is 6 more than one third of it,

Let X be the number
Then 50% of the number is 50% X
One third of it is (1 / 3) X
So 50% X - (1 / 3) x = 6
x=36
The number is 36

Is the friction force related to the contact area?

Nothing to do with it
F friction = n pressure * u.u dynamic friction coefficient is only related to the smoothness of the contact surface. For static friction, the maximum static friction can be regarded as sliding friction, so it can also be regarded as related to the smoothness of the contact surface

In AX = B, a is not equal to o, the equation has unique solution: the equation has innumerable solutions: the equation has no solution:

Where AX = B,
When a ≠ 0, the equation has a unique solution: x = B / A;
When a = 0, B = 0, the equation has innumerable solutions: any real number;
When a = 0, B ≠ 0, the equation has no solution

AB is 240 kilometers away from each other. The speed of a bus is 80 kilometers per hour, and that of a car is 100 kilometers per hour. If two cars start from both ends at the same time, how many hours

240 ÷ (80 + 100) = 1 and 1 / 3 of an hour

Given the square of (2008-A) + the square of (A-2007} = 1, find the value of (2008-A) (A-2007)

Let x = 2008-A, y = A-2007
The original formula is: x ^ 2 + y ^ 2 = 1
(X+Y)^2-2XY=1
2XY=(X+Y)^2-1^2
2XY=(X+Y-1)(X+Y+1)
I.e. 2 (2008-A) (A-2007) = (2008-A + a-2007-1) (2008-A + A-2007 + 1)
(2008-A)( A-2007)=0

Factorization 4x ^ 3 + 4x ^ 2 + X?

4x^3+4x^2+x
=x(4x^2+4x+1)
=x(x+1)^2

The fruit shop has bananas x kg, and the weight of apples is five times that of bananas. How many kg do bananas and apples weigh?

The fruit shop has bananas x kg, and the weight of apples is five times that of bananas. Bananas and apples weigh 6x kg

-2 less than or equal to x less than or equal to 2, inequality x square + ax-3a

A > - x ^ 2 / (x-3)
Find the maximum value of - x ^ 2 / (x-3) in [- 2,2]
The derivative is f '= - x (X-6) / (x-3) ^ 2
In [- infinity, 0] decreasing, [0,6] increasing, [6, infinity] decreasing
Substituting - 2 and 2 into - x ^ 2 / (x-3) respectively, the maximum value is 4
So a > 4

What is the cubic power of X + the square of x-x + 1?
Is there any formula for finding the root of a simple point to the cubic power of one variable? There are so many on the Internet that I don't know which one it is

X & # 179; + X & # 178; - x + 1 is the simplest form in the range of real number. It may be that a symbol in the formula X & # 179; + X & # 178; - x + 1 is wrong, such as X & # 179; - X & # 178; - x + 1 = x & # 178; (x-1) - (x-1) = (x-1) (X & # 178; - 1) = (x-1) &# 178; (x + 1), etc