The slope of this equation is
3
Answer:
The speed of the current is 3 miles per hour
Step-by-step explanation:
The equations for rate (r), distance (d), and time (t) are ⇒ d = rt, r = d/t, = t = d/r
Let x = speed in still water
Let c = speed of the current
The main difference with these problems is rate needs to be expressed using two variables because moving upstream the current is against you and downstream it moves with you.
Distance Rate Time
Upstream x − c
Downstream x + c
The distance column with the numbers from the problem and the value for speed in still water for x.
Distance Rate Time
Upstream 4 5 − c
Downstream 16 5 + c
The column for time using the other two columns knowing that rate, distance ⇒ time = Distance Rate Time
Upstream 4 5 − c
5 − c
4
Downstream 16 5 + c
5 + c
16
“It takes as long …” from the problem means that the two times are equal to each other. So, the equation can be written as:
4/5− c = 16/5 + c ⇒ Solve by cross-multiplying ⇒ 5(4 + c) = 16 5( − c) ⇒ c = 3
Answer:
450 feet
Step-by-step explanation:
60ft = 4 seconds
x ft = 30 seconds
(cross multiply)
60 * 30 = 4x
1800= 4x
(divide both sides by 4)
x= 1800/4= 450
Answer:
39
Step-by-step explanation:
1. Use the Pythagorean theorom: a^2+b^2=c^2.
C is the missing side here, which is the hypotenuse of the triangle. The other two sides and be put into the equation either way. Doesn't matter the order.
15^2 + 36^2 =c^2
2. Evaluate 15^2 and 36^2 and add the results.
15^2 = 225
36^2 = 1,296
225+1,296= 1,521
3. Take the square root of the answer.
√1521 = 39
