It is known that the first side of a triangle is (2a + b) cm, the second side is (a-b) cm longer than the first side, and the third side is ACM shorter than the first side (1) The length of the second side is () cm, and the length of the third side is () cm (2) : find the perimeter of the triangle
(1) ∵ the second side is (a-b) cm longer than the first side,
The length of the second side is (2a + b) + (a-b) = 2A + B + A-B = 3A (CM);
∵ the third side is shorter than the first side ACM,
The length of the third side is (2a + b) - a = a + B (CM)
(2) Perimeter of triangle = (2a + b) + 3A + (a + b) = 6A + 2B (CM)
If the perimeter of the triangle is 48, the first side is 4A + 3b, and the second side is 2a-b less than 2 times of the first side, then the third side is 4A + 3B______ .
48-(4a+3b)-[2(4a+3b)-(2a-b)]=48-4a-3b-[8a+6b-2a+b]=48-4a-3b-8a-6b+2a-b=48-10a-10b.
The length of one side of the rectangle is (2a + b), and the other side is smaller than it (a-b). How about the perimeter of the rectangle
Judge, negative number is the number with negative sign, see the order, have a reason
Right! Rational numbers are divided into positive numbers, negative numbers and 0, positive numbers and 0 are not signed, then negative numbers with negative signs are negative numbers. If not, they are not negative numbers
What's the difference between negative numbers and numbers with negative signs
It's a big difference, isn't it
-1 is negative
-(-1)=1
Number with negative sign
Does a number with a negative sign have to be negative
If the next character is a number and is the first character, and there are no other special characters in the string, that's right
Judgment 1. Negative numbers are numbers with negative signs, right? 2. Positive numbers are positive rational numbers, right?
Judgment
1. Negative numbers are numbers with negative signs, right?
incorrect.
For example:
x = -1
-X = 1, which is a positive number
2. A positive number is a positive rational number, right?
incorrect.
A positive number is a positive real number