So, let's say the soft drink equals y and the sandwich equals x.
x + y = 9.9
The sandwich costs 3.5 times as much as the soft drink
x = 3.5y
Therefore, we can replace x with 3.5y since they're the same thing
3.5y + y = 9.9 <-- That's the equation :)
Answer:
subtraction
Step-by-step explanation:
x +15 = 9
-15 = -15
x = -6
Answer:
Rate of change of money in Michael's account will be $20 per week.
Step-by-step explanation:
If we draw a graph for the duration of investment on x-axis and amount in the account on y-axis, ordered pairs for both the conditions will be,
After 6 weeks, amount in the account = $140
Ordered pair : (6, 140)
After 12 weeks, amount in the account = $260
Ordered pair : (12, 260)
Rate of change in hi account per week = 
= 
= 
= $20 per week
Therefore, rate of change of money in Michael's account will be $20 per week.