The sum of twice a number and seven is 13. Find the number.
1 answer:
Answer:
<h2>The answer is 3</h2>Step-by-step explanation:
Let the number be x
The statement
twice a number is written as
2x
The sum of twice a number and seven is written as
2x + 7
The result is 13
So we have
2x + 7 = 13
Subtract 7 from both sides
That's
2x + 7 - 7 = 13 - 7
2x = 6
Divide both sides by 2
That's
We have the final answer as
<h2>x = 3</h2>Hope this helps you
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Answer:
Δy = 0.822
dy = 0.6
Step-by-step explanation:
Let us use the rules:
If f(x) = y, then
- dy = f'(x) . dx
- Δy = f(x + Δx) - f(x)
∵
- Differentiate it (remember the differentiation of is
∴
∴
∵ dy = y' . dx
∴
∵ x = 0
∵ dx = Δx
∵ Δx = 0.6
∴ dx = 0.6
- Substitute x by 0 and dx by 0.6 in y'
∴
- Remember any number to the power of 0 is 1 except 0
∵ = 1
∴ dy = 0.6
∵ Δy = f(x + Δx) - f(x)
∵ x = 0
- Substitute x by
∴ f(0) =
∴ f(0) = 1
∵ Δx = 0.6
∵ x + Δx = 0 + 0.6
∴ x + Δx = 0.6
- Substitute x by 0.6
∴ f(0.6) =
∴ f(0.6) = 1.8221188
∵ Δy = f(0.6) - f(0)
∴ Δy = 1.8221188 - 1
∴ Δy = 0.8221188
- Round it to the nearest 3 decimal places
∴ Δy = 0.822