This is a classic question on Speed, time, & distance.
1. When time traveled in each segment is constant, then average speed is simple mean of speeds.
2. When distance traveled in each segment is constant, then average speed is reciprocal of simple mean of reciprocal of speeds. It is basically called Harmonic mean.
So this question falls in the category of 2.
=> So, average speed = Reciprocal of mean of reciprocals of 40 & 50.
=> Average speed = Reciprocal of mean of 1/40 & 1/50.
<span>=> Average speed = Reciprocal of (1/40 + 1/50)/2 = Reciprocal of (5+4)/400 = 44 4/9 .
Hope this helps</span>
How to solve your problem
Topics: Algebra, Quadratic Equation
2
+
1
=
−
3
2x+1=x-3
2x+1=x−3
Solve
1
Subtract
1
1
1
from both sides of the equation
2
+
1
=
−
3
2x+1=x-3
2x+1=x−3
2
+
1
−
1
=
−
3
−
1
2x+1{\color{#c92786}{-1}}=x-3{\color{#c92786}{-1}}
2x+1−1=x−3−1
2
Simplify
Subtract the numbers
Subtract the numbers
2
=
−
4
2x=x-4
2x=x−4
3
Subtract
x
x
from both sides of the equation
2
=
−
4
2x=x-4
2x=x−4
2
−
=
−
4
−
2x{\color{#c92786}{-x}}=x-4{\color{#c92786}{-x}}
2x−x=x−4−x
4
Simplify
Combine like terms
Multiply by 1
Combine like terms
=
−
4
x=-4
x=−4
Solution
=
−
4
Answer:
x ≤ 7
Step-by-step explanation:
(2x-4) + 110 ≤ 120
Combine like terms
2x +106 ≤ 120
Subtract 106 from each side
2x+106 -106 ≤ 120-106
2x ≤ 14
Divide each side by 2
2x/2 ≤ 14/2
x ≤ 7
Answer:
24° and 66°
Step-by-step explanation:
Angle 1 = x
Angle 2 = x + 42°
x + x + 42° = 90°
Subtract 42° from both sides and add
2x = 48°
Divide by 2
x = 24°
24° and 66°
Hope this was useful to you!
