This simplified is 126x so that is equivalent to this expression
Answer:
x=4, y=3
Step-by-step explanation:
maths
Answer:
It will take the chopper 2 seconds to reach the ground
Step-by-step explanation:
When the helicopter reaches the ground , then it is at height zero.
Thus, we equate the modeled equation to zero.
0 = -16t^2 + 8t + 48
This is same as;
16t^2 -8t -48 = 0
We divide through by 8
2t^2 - t - 6 = 0
2t^2 - 4t + 3t - 6 = 0
2t( t- 2) +3 (t -2) = 0
(2t + 3)(t-2) = 0
2t + 3 = 0 or t - 2 = 0
2t = -3 or t = 2
t = -3/2 or t = 2
t = -1.5 or t = 2
Since time cannot be negative, we select t = 2 and ignore t = -1.5
Thus, it will take the chopper 2 seconds to reach the ground
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
