Answer:

Step-by-step explanation:
The LCM of 14, 21 and 6 is 42
We require to change the fractions to fractions with a denominator of 42
+
+ 
=
+
+
← add the numerators, leaving the denominator
= 
=
← divide both values by 2
=
← in simplest form
I think first 80 and second 90
Answer:
The maximum number of sandwiches she can buy is 24.
Step-by-step explanation:
We can create a function to represent the cost of her team's lunch in function of the number of people in the team. We have:

Since she needs to stay on budget, the cost has to be less or equal to 170, therefore:

Since she can't buy 0.8 sandwiches, the maximum number of sandwiches she can buy is 24.
Answer:
3m − 5
Step-by-step explanation:
1. x = 2
2. x = 9
3. a = 3
4. x = 13
5. c = 3
6. s = 3
7. x = 7
8. c = 0
9. b = 1
10. c = 4
11. x = 4
12. x = 8
13. x = 12
14. y = 10
15. x = 11
16. x = 10
17. x = 6
18. x = 11