Let daniel's age = d and let jessica's age = j
let your current age = x and your wife's current age = y
x = 5d (given in question)
∴ x - 5d = 0
x + 21 = 2(d+21) (given in question)
∴ x + 21 = 2d + 42
∴ x - 2d = 21
We can solve these two rearranged equations simultaneously by multiplying the first equation by -1 and adding them. This gives us the following:
3d = 21
∴ d = 7
This means that daniel is currently 7 and (if we substitute d = 7 into one of the equations) you are 35. We use a similar method for your wife's and jessica's current ages.
y = 7j (given in question)
∴ y - 7j = 0
y + 8 = 3(j + 8)
∴y + 8 = 3j + 24
∴ y - 3j = 16
If we use a similar method of elimination we get this:
4j = 16
∴ j = 4
Hence, from this we can concur that daniel is 7 and jessica is 4.
Answer:
See Explanations
Step-by-step explanation:
The steps in the question isn't clear enough, however the question is answerable.
From the question, we understand that one model shows that:
200 is 10 times 20
While the second model shows that
200 is 10 times 2
The first model that says
200 = 10 times 20 makes sense.
This is so, because 200 = 20 * 100
While the other model which says
200 = 10 * 2 is nonsense.
This is so because, 200 ≠ 10 * 2
Answer:
2 or 3 im not sure but choes 2
Step-by-step explanation:
Answer:
x=1
x=-5
Step-by-step explanation:
we know that
The solution of the system of equations is the intersection point both graphs
In this problem there are two intersection points
so
The system has two solutions
we have
one solution is the point (-4.9, 5.4) and the other (0.92, -0.42)
see the attached figure
therefore
x=1
x=-5
Step-by-step explanation:
