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:
Step-by-step explanation:
(2n - 3)(5n + 6) = 2n*(5n + 6) -3*(5n +6)
=2n*5n + 2n*6 -3*5n + (-3)*6
=10n² + 12n - 15n - 18
= 10n² -3n - 18
First you have to set up your equation. 5x+80 and x+15.
The anwser is b because it is 150 dollars
Answer:
$78.69
Step-by-step explanation:
63.04+58.27=121.31
200-121.31=78.69
