Derek is four times as old as sarah. two years ago the sum of their ages was 36. how old is each now?

1 answer:

4 0

Let's write a system of equations. We will use D for Derek's age and S for Sarah's age:

D = 4S

(D - 2) + (S - 2) = 36

We can simplify the second equation:

D + S - 4 = 36

D + S = 40

Now we can use substitution to plug 4S in for D in the second equation:

(4S) + S = 40

5S = 40

S = 8

Sarah is 8 years old.

You might be interested in

What is the smallest, positive integer value of x such that the value of f(x) = 2x + 3 exceeds the value of g(x) = 50x + 5?

weeeeeb [17]

F(x) > g(x)
2^x + 3 > 50x + 5

for x = 3 , f(3) > g(3)
11 > 155 (false)

for x = 10 , f(10) > g(10)
1027 > 505 (true)

for x = 9 , f(9) > g(9)
515 > 455 (true)

for x = 8 , f(8) > g(8)
259 > 405 (false)

the smallest,positive integer value of x is 9 since the value of 9 is the last number to exceeds g(x)

7 0

3 years ago

A community center rents their hall for special events. They charge a fixed fee of $200 plus an hourly fee of $22.50. Lin has $3

Karo-lina-s [1.5K]

Answer:

No, 6 hours would cost $335, 35 over her limit of $300.

Step-by-step explanation:

she has to pay $200 plus 22.50 for every hour she rents. So, if she rents for 6 hours, she has to pay $200 + 6(22.50) or $200 + 135=335. She only has $300 so she can’t afford the event.

3 0

2 years ago

0.02 is 1/10 of 0.2. True or false ??

Len [333]

Answer:

true

Step-by-step explanation:

1/10 * 0.2 = 0.02

Hope this help :)

6 0

3 years ago

Situation: Florentina the Baker has already prepared 4 kilograms of dough. She

insens350 [35]

Answer: 4 kilograms of dough and will continue preparing 1 kilogram of dough every hour.

Step-by-step explanation:

5 0

3 years ago

Data from the Centers for Medicare and Medicaid Services indicates that the annual per capita out-of-pocket expenses for health

Talja [164]

Answer:

During the year 2021.

Step-by-step explanation:

As we have a function that defines the annual per capita out-of-pocket expenses for health care, we can work with it.

Knowing that, we clear x (this is the number of years past the year 2000, so it will contain our desired information).

$y=39.6x+543\Leftrightarrow x=\frac{y-543}{39.6}$

Now, as we want to know when are the per capita out-of-pocket expenses for health care predicted to be $1400, and this total is our variable y, then

$x=\frac{1400-543}{39.6}\approx 21.6$

Finally, we know that x is the number of years past the year 2000, so the answer is that during the year 2021, the per capita out-of-pocket expenses for health care are predicted to be $1400.

3 0

3 years ago