1. we know she needs 3 packs of biscuits
2. Shop A you only need to pay for 2 packs
3. Shop B you only need to pay for 2 packs
4. Shop C you need to pay for all three
5. so we know C is out of the option.

so shop A and B will cost the least
Answer:
B.
Step-by-step explanation:
she only has $60 to spend therefore, she has the option of spending all of it, or less. However she cannot spend money she doesn't have.
Answer:
y = 30x + 20
Step-by-step explanation:
y = mx + b
find b
b=20
find m
m=30
4.5/3 = x/5
then:
x = 5 * 4.5 / 3 = 15/2 = 7.5
hope that helps
If you know that y = 6. You just have to switch Y by 6.
x + 2y = 16
x + 2*6 = 16
x + 12 = 16
x = 16 - 12
x= 4
4 + 2*6 = 16
Hope this helps !
Photon