In order to find the number of boys and girls you must understand the equation needed.
The total number of girls plus boys is indicated as 29 students.
You then have to understand that there are "4 less than twice the number of boys". To start, add 4 to 29 which equals 33 to eliminate the "4 less". When it states twice the number of boys that is indicated that there should be 2x as many girls than boys. In order to view this as fractions, you would have 2/3 the class as girls and 1/3 as boys. 2/3 of 33 would be 22. Now that you have that you need to add back the "4 less" by subtracting 4 from your 22 be get 18. If there are 18 girls in the class you can then find the number of boys by taking 29-18 which would be 11 boys.
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