Answer:
3
Step-by-step explanation:
(3x^6+4x+3)+(3x^8+6x)=
3x^6+4x+3+3x^8+6x=
3x^8+3x^6+(4+6)x+3=
3x^8+3x^6+10x+3
Answer: Option C. 3x^8+3x^6+10x+3
1.55 i did that math too it was kinda hard but i did it
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
