It is known that 2A + B / 3 = 3a-2b / 8 = 3
(2a+b)/3=(3a-2b)/8=3
2a+b=9 ...(1)
3a-2b=24 ...(2)
(1)*2+(2):4a+3a=18+24,7a=42,a=6
b=9-2a=-3
Simplify 3A - [2A - (2b-c)] = B and find the value when a + B = 5 and C = 4
3a-[2a-(2b-c)]-b
=3a-2a+(2b-c)-b
=a+b-c
=5-4
=1
Explain the following formula "based on life experience
&Frac12; (a + b) C (the first number is half)
(1+a%)x
If the average value of a and B is multiplied by C, a and B can be regarded as the monthly salary of the couple, then this formula is the average salary of each couple for C months
A is the interest rate, X is the principal, (1 + a%) x is the principal and interest after one year
What quantitative relations do the algebraic expressions 3a and 2a-b represent? Two corresponding examples are given
3A: a yuan for each book. I bought three copies, a total of 3A yuan
A yuan per kilogram of apple, bought 3kg, a total of 3A yuan
2a-b: a yuan for each book, two cheap B yuan, a total of 2a-b yuan
A yuan per kilogram of apples, buy two kilos cheap B yuan, a total of 2a-b yuan
There are many examples
As an example, the quantity relation in the problem can be expressed by the algebraic formula 3A + 2B
It costs a yuan for big soft copy and B yuan for small soft copy. It costs (3a + 2b) yuan to buy 3 big soft copies and 2 small soft copies
Given that the value of the algebraic formula 2x-y is 3, find the value of the algebraic formula 3-x + 2 / y
2X-Y=3
Y/2-X=-3/2
3-X+2/Y=3-3/2=3/2
That's it~
The meaning of the flat of the algebraic formula a square + b square / (a-b) is
Two squares with side lengths of a and B (a ≠ b) can be decomposed into squares with side lengths of | A-B | and (a + b) / (a-b)
According to life experience, the algebraic formula A / 52% is explained
There are a female students in class three of seven years, accounting for 52% of the total number of students in the class, and a / 52% of the total number of students in class three of seven years
When x is equal to what number, the value of algebraic formula (x-1) / 3 and X + 2 are equal
-7/2
The solution set of inequality X-2 ≥ 3 (x + 1) is
X-2≥3(X+1)
X-2≥3X+3
3X-X≥-2-3
2X≥-5
X≥-2/5