Answer:
Roy is 10 years old at present and Joan is 5 years old at present
Step-by-step explanation:
Let
x----> Roy's age
y----> Joan's age
we know that
x=2y ----> equation A
(x+3)+(y+3)=21 ----> equation B
substitute equation A in equation B
(2y+3)+(y+3)=21
solve for y
3y+6=21
3y=21-6
3y=15
y=5 years
Find the value of x
x=2y ----> x=2(5)=10 years
therefore
Roy is 10 years old at present
Joan is 5 years old at present
Answer:
The total cost C = $10 + $0.05·x
Step-by-step explanation:
The given parameters are
The cost of the cell phone plan per month = $20
The number of minutes of free calls that one can make in a month = 200 minutes
The cost of additional minutes of cell phone call = 5 cent
5 cents to a dollar = $0.05
The total number of minutes of calls made in a month = x
The time duration of a person's usage of the cell phone in a month > 200 minutes
The total cost C of a person's usage per month is given by;
C = $20 + $0.05 × (x - 200) = $20 + 0.05·x - $10
C = $10 + $0.05·x
Where x > 200.
Hello There!
X=2
To solve this, we first need to understand that when we see an X in parentheses, we multiply the number before it in this case 4 by X.
The answer is 2 because we multiply 4 by 2 which is the x value so 4*2 is equal to 8 and they we add 9 to it because the sum of 6 and 3 is 9.
Finally, our answer we get is 17 so our X value is 2.
Have A Great Day!