Let us assume the total amount of meal charge paid by Michael without tax = x
Then
Amount paid to the waiter by Michael = 15x/100
Sales tax paid by Michael = 5x/100
Now we get the equation as
x + (5x/100) + (15x/100) = 18
(100x + 5x + 15x)/100 = 18
120x/100 = 18
120x = 1800
x = 1800/120
= 180/12
= 15 dollars
So the amount paid by Michael for the meal before tax and tip is $15. I hope the procedure is clear enough for you to understand.
You need to factor the numerator and denominator...
(2x^2+4x-2x-4)/(2x^2-2x-2x+2)
(2x(x+2)-2(x+2))/(2x(x-1)-2(x-1))
((2x-2)(x+2))/((2x-2)(x-1)) so the (2x-2)s cancel out leaving
(x+2)/(x-1)
Since 1 lap I every 6 minutes then 30\6 is 5 so the answer is 5 LAPS
