Mom drove for 11 hours.
Dad drove for 3 hours.
<u>Step-by-step explanation</u>:
- Total distance = 895 miles
- Mom drove a speed of 65 mph
- Dad drove a speed of 60 mph
Let 'x' be the number of hours drove by mom.
Let 'y' be the number of hours drove by dad.
x + y = 14 ---------------(1)
65x + 60y = 895 ---------(2)
Multiply eq(1) by 60 and subtract eq(2) from (1),
60x + 60y = 840
-(<u>65x + 60y = 895</u>)
<u> -5x = -55 </u>
x = 55/5
x = 11
∴ Mom drove for 11 hours.
Substitute x=11 in eq(1)
11+y = 14
y = 3
∴ Dad drove for 3 hours.
Answer:
Given:
Diameter = 38cm
Radius = Diameter /2
Radius = 38 / 2
Step-by-step explanation:
Answer:
C
Step-by-step explanation:
In general for arithmetic sequences, recursive formulas are of the form
aₙ = aₙ₋₁ + d,
and the explicit formula (like tₙ in your problem), are of the form
aₙ = a₁ + (n - 1)d,
where d is the common difference. So converting between the two of these isn't so bad. In this case, your problem wants you to have an idea of what t₁ is (well, every answer says it's -5, so there you are) and what tₙ₊₁ is. Using the formulas above and your given tₙ = -5 + (n - 1)78, we can see that the common difference is 78, so no matter what we get ourselves into, the constant being added on at the end should be 78. That automatically throws out answer choice D.
But to narrow it down between the rest of them, you want to use the general form for the recursive formula and substitute (n + 1) for every instance of n. This will let you find tₙ₊₁ to match the requirements of your answer choices. So
tₙ₊₁ = t₍ₙ₊₁₎₋₁ + d ... Simplify the subscript
tₙ₊₁ = tₙ + d
Therefore, your formula for tₙ₊₁ = tₙ + 78, which is answer choice C.
Answer
-8
r > 0
Step-by-step explanation:
you know that r is less than or equal to -8, so you write that, and then you know that r is also greater than 0, so then you add that to it, and then you have the answer. r will be in the middle because it is the range of what are can be.