The number of boys in a class is 6 more than 5 / 7 of the whole class, and the number of girls is 4 less than 1 / 4 of the whole class

The number of boys in a class is 6 more than 5 / 7 of the whole class, and the number of girls is 4 less than 1 / 4 of the whole class

Set the class as X people
5/7x-6=1/4x+4

Grade 7 rational number of four mixed computing problems, urgent ~ fast~

1. When doing the mixed operation of rational numbers, we should pay attention to the order of operation; first multiply the square, then multiply and divide, and finally add and subtract; at the same level, we should carry out the operation from left to right; if there are brackets, we should first calculate the operation in the brackets, and then carry out the operation in the order of small brackets, middle brackets, and curly brackets

The average value of the three numbers is 50. Now change one of the numbers to 60 and the average value to 55. What was the original number?

Original = 60-3 × (55-50) = 45

Simple calculation of 0.89 × 12.5-0.9 × 1.25

0.89×12.5-0.9×1.25
=0.89×12.5-0.09×12.5
=(0.89-0.09)×12.5
=0.8×12.5
=10

Xiao Ming bought some story books and interesting mathematics for 50 yuan. The salesman got 8 yuan back. Please help Xiao Ming judge if he can get it back
5 yuan for a story book and 10 yuan for a talent interesting math book

The money you got back must be wrong
Because no matter how you buy it, you only have 0 or 5 to pay for it. When you get 8 yuan back, you actually spend 50-8 = 42 yuan, and the mantissa is 2
So it's definitely not right

How do you spell English words 20 30 40 50 60 70 80 90? It's urgent

twenty
thirty
forty
fifty
sixty
seventy
eighty
ninety

How to move a match so that 7 minus 11 equals 4

7-11=4 7=11-4

Xiao Ming and Xiao Gang are on their way to school. He asks him what he wants to do in his extracurricular activities this afternoon

Change him to Xiao Ming or Xiao Gang

Is 2000 a leap year or a normal year

In the Gregorian calendar (Gregorian calendar), the year with a leap day is called a leap year. Generally, the year is 365 days, and the leap year is 366 days

Minus 8 times (minus 1 / 6 minus 5 / 12 plus 3 / 10) times 15 =? Simple algorithm

Minus 8 times (minus 1 / 6 minus 5 / 12 plus 3 / 10) times 15
=(1/6+5/12-3/10)x120
=1/6x120+5/12x120-3/10x120
=20+50-36
=34