1. 7/12, 0.75, 5/6
2. 3.25, 3 3/8, 3 2/5
Well,
We are given a direct proportion problem.
x varies directly as y.

When y = -5, x = 15.

Now, we are told to find x when y = 3.

We just have to recognize that the complete case is equal to the incomplete case. In other words, we set the -3 equal to the x/3.

Multiply both sides by the LCM.
LCM of -1 and 3 = 3
-9 = x
When y = 3, x = -9.
standard form for a linear equation means
• all coefficients must be integers, no fractions
• only the constant on the right-hand-side
• all variables on the left-hand-side, sorted
• "x" must not have a negative coefficient
2x + y = -9.
In this case, you already used 310 minutes out of 500 minutes monthly. So the remaining time for your cell phone should be: 500 minutes -310 minutes= 190 minutes.
You still have 1 week this month, that means the 190 mins time must be divided into 1 week or 7 days. Then the duration you of cell phone use for each day should be: 190 minute/7days= 27.14 minutes/day