Answer:

Step-by-step explanation:
Let
x ----> the length of Zach's car
y ----> the length of Ginny's car
we know that
The sum of the lengths of both cars is 30 inches
so
----> equation A
Ginny's car is 2 more than 3 times the length of Zach's car
so
----> equation B
substitute equation B in equation A

Answer:
octagon, because 4 + 4 = eight sides, and octagons have 8 sides
Step-by-step explanation:
Hope that helps!
Answer:
2x
Step-by-step explanation:
aka 2
Answer:
Step-by-step explanation:
p + c = 110
p = c + 100
c + 100 + c = 110
2c + 100 = 110
2c = 110 - 100
2c = 10
c = 10/2
c = 5 .......cost of the phone case
p = c + 100
p = 5 + 100
p = 105 <=== cost of the phone