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
Times -7 by everything in the parentheses. so
-7 times 5y=-35y
-7 times -2u=14u
-7 times -5 = 35
therefore 35y+14u+35
57 = 7 + 2x
50 = 2x
x = 25
x being the number of pages read last week
Hope this helps a little!!
<span>12/4 irrational or rational number
is a irrational number </span>
<span>3(x-4)= -5
Multiply 3 by x and -4
3x-12= -5
Add 12 to both sides
3x= 7
Divide 3 on both sides
Final Answer: 7/3 or 2 1/3
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