Answer:
The speed on motorboat is 20 mph
Step-by-step explanation:
here, we want to find the speed on the motorboat
if he has a speed of x mph on the motor boat, his speed on the ski will be (x + 10) mph
The total hours is 4 hours
Mathematically; speed = distance/time
Time on ski is 27/x+ 10
Time on motor boat is 62/x
The addition of both is 4
Thus;
27/(x + 10) + 62/x = 4
27(x) + 62(x + 10) = 4(x)(x + 10)
27x + 62x + 620 = 4(x^2 + 10x)
89x + 620 = 4x^2 + 40x
4x^2 -49x-620 = 0
using the quadratic formula;
{-b ± √(b^2-4ac)}/2a
where a = 4, b = -49 and c = -620
= 49 ± √(-49)^2-4(4)(-620)/8
So we have
49+ 111/8 or 49-111/8
Speed cannot be negative
(49 + 111)/8
= 20 mph
Answer:
I think you may have forgot to put in the rest of the question mate
Step-by-step explanation:
Infinitely many because if you subtract 7x from both sides, you get 4 = 4, which is true at all times no matter what x is.
Diameter = 2*(radius)
The radius is half of the diameter, so if you were given the radius and need to find the diameter, multiply the radius by two. If you were given the diameter and need to find the radius, divide the dimaeter by two
12 x 15 = 180
180 x 2 = 360
360 square yards of carpet should be ordered.
