Answer: 5.3 Hours
Step-by-step explanation: 140 mi there at 56 mi per hour would be 2.5 hours. Then back 140 mi at 50 mi/h would be 2.8. 2.5 plus a 2.8 is 5.3 hours
Let's first define variables.
y: number of shares of $ 10
x: number of shares of $ 12
We write the system of equations:
10x + 12y = 210
y = 2x + 5
Solving the system:
x = 75/17
y = 235/17
Answer:
she has:
75/17 shares of $ 12
235/17 shares of $ 10