Answer:
Thus, the value of x = -36 when y = 15
Step-by-step explanation:
We know that if y varies directly with x, we can express the relationship such as
y ∝ x
y = kx
k = y/x
where 'k' is called constant of variation.
Given
y = -5
x = 12
Using the equation
k = y/x = -5/12
Thus, the value of k = -5/12
Finding x when y = 15
y = 15
k = -5/12
substituting y = 15 and k = -5/12 in the equation
y = kx
15 = -5/12 (x)
15×12 = -5x
180 = -5x
divding both sides by -5
-5x/-5 = 180/-5
x = -36
Thus, the value of x = -36 when y = 15
The equation for the first option is Y=10x + 200
The equation for the second option is Y=30x + 100
X = one month
To find when they would be the same about you have to set the equations equal to each other
10x + 200 = 30x + 100
-10x -100 -10x -100
100= 20x
5 = x
After five months she would save the same amount. To find how much is saved you have to plug in 5 for x in one of the equations. You can always double-check 5 by plugging it in both equations and making sure you get the same answer
Y= 10(5) + 200 = 250
Y= 30(5) + 100 = 250
She would have saved $250 after five months by using either method
Answer:
Kevin will earn the money before than Philip
Philip needs at least 4 weeks
Kevin needs at least 3 weeks
Step-by-step explanation:
Let's call x to the number of weeks
Philip works 6 hours each weekend, which means 6 hours per week, earning $8.75 per hour, which is equivalent to 6*8.75 = $52.5 per week
Philip has already saved $45. Then he needs the next number of weeks:
52.5*x + 45 = 225
x = (225 - 45)/52.5
x = 3.4
Philip needs at least 4 weeks
Kevin works 3 hours per day for 3 days a week, which means 9 hours per week, earning $7.5 per hour, which is equivalent to 9*7.5 = $67.5 per week
Kevin has already saved $30. Then he needs the next number of weeks:
67.5*x + 30 = 225
x = (225 - 30)/67.5
x = 2.9
Kevin needs at least 3 weeks
The coefficient is 2 (it is always the number before the variable)