Answer:
Explanation:
<u>1. Data:</u>
i) Distance traveled by the cars:
ii) Speed of the cars:
iii) Time to arrive at the suburb:
- t₂ - t₁ = 2 hour ⇒ t₂ = t₁ + 2
<u>2. Equations:</u>
time = distance / speed
- t₂ = 480 / v₂
- t₁ = 480 / v₁ = 480 / (v₂ + 20)
t₂ - t₁ = 2 hour
↓ ↓ ↓
480/v₂ - 480/ (v₂ + 20) = 2
<u>3. Solve the equation</u>
480(v₂ + 20) - 480(v₂) = 2 × (v₂ + 20) (v₂)
240(v₂ + 20) - 240(v₂) = (v₂ + 20) (v₂)
240v₂ + 4800 - 240v₂ = (v₂)² + 20v₂
(v₂)² + 20v₂ - 4800 = 0
(v₂ + 80) (v₂ - 60) = 0
v₂ = - 80
v₂ = 60
Only the positive solution has physical meaning:
- v₁ = 60km/h + 20km/h = 80km/h ← answer
Answer:
Given: R is the midpoint of QS.
QS=40
Now,
QR=40/2(R IS THE MIDPOINT)
=20
Answer:
C = -13.78
Step-by-step explanation:
9514 1404 393
Answer:
5, 10, 20
Step-by-step explanation:
Suppose the three numbers are x, 2x, and 4x. Then they have the required ratios. After the transformation, we have ...
((x+3) +(4x -8))/2 = 2x . . . . . 2nd term is average of 1st and 3rd
5x -5 = 4x ⇒ x = 5
The original numbers are 5, 10, 20.
_____
After the adjustment, the arithmetic sequence is 8, 10, 12.
