Answer:
12 students
Step-by-step explanation:
Given

Required
Determine the number of students that eat lunch once a week
In Sets;
If out of 9, at least 7 eats one a week then
9 - 7 eats lunch once a week

<em>In other words;</em>
2 out of 9 students eat lunch once a week
Number of students in this category is then calculated as thus;




Answer:
3
Step-by-step explanation:
mhm for your brother
anyways...
2x-3+6x = 21
Adding like terms
8x -3 = 21
Adding 3 on both sides
8x = 24
Dividing both sides by 8
x = 3
5^0 x 5^4 1 x 625 625
------------- = ---------- = ----- = 1 B
5^3 x 5^1 125 x 5 625