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
Step-by-step explanation:
the answer is the third one
hope it helps and if u need a explanaton I can help
The recommended weight of a soccer ball is 430 grams. The actual weight is allowed to vary by up to 20 grams.
a. Write and solve an absolute value equation to find the minimum and maximum acceptable soccer ball weights.
Answer:
1 + sin2x
Step-by-step explanation:
Given
(sinx + cosx)² ← expand using FOIL
= sin²x + 2sinxcosx + cos²x
[ sin²x + cos²x = 1 and sin2x = 2sinxcosx ]
= 1 + sin2x
Answer:
Step-by-step explanation:
<u>Find the sum:</u>
- 1/2n(n+1) + 1/2(n+1)(n+2) =
- 1/2(n² + n) + 1/2(n² + 3n + 2) =
- 1/2(n² + n + n² + 3n + 2) =
- 1/2(2n² + 4n + 2) =
- n² + 2n + 1 =
- (n + 1)²
Proved
