Twice (2 times) the difference (subtraction) of a number (y) and 7 equals 3.
2*(y-7) = 3
hope this helps :)
Answer:

Step-by-step explanation:











Hope I helped!
Best regards! :D
~
Answer:
Numbers of students at a primary school before= 240
Number of increased students =42
Again,
Increased number of students in percent(%)= 42/240×100%= 17.5%
Therefore 17.5% students are increased this year.