Answer:
7 < x < 8
Step-by-step explanation:

Answer:
Any value of x
makes the equation true.
All real numbers
Interval Notation:
(−∞,∞)
Step-by-step explanation:
Any value of x makes the equation true.
Answer:
6 year's old
Step-by-step explanation:
Grandma is G and Robin is R
G=7R
G+12=3(R+12)
G+12=3R+36
7R+12=3R+36
7R-3R=36-12
4R=24
R=6
Robin is 6 years old
Answer: x = 5; y = -5

Step-by-step explanation: