To find the perimeter you do length + width so you do 12.4 + 5.9 to get the perimeter.
sqrt (5x - 9) - 1 = x
sqrt(5x - 9) = x + 1
Square both sides:_
5x - 9 = x^2 + 2x + 1
x^2 - 3x + 10 = 0
(x - 5)(x + 2) = 0
x = 5 or -2.
Lets look for for any extraneous solutions:-
x = 5 ; sqrt (5*5-9) - 1 = sqrt16 - 1 = 3 and x = 3 (right hand side of equation)
so x = 5 is a solution
x = -2: sqrt(5*-2 - 9) - 1 = sqrt (-19) - 1 and x = -2 so this is extraneous
Answer:- One solution x = 5
Total number of cards = 52
Number of clubs = 13
Number of cards that is not a club = 39
P(club + not a club) = (13/52) (39/51) = 13/68
Answer: 13/68
Let the time he spent bicycling at 11 mph be x and the time spent bicycling at 15 mph be y, then
x + y = 60 . . . (1)
7x + 11.75y = 600 . . . (2)
(2) x 7 => 7x + 7y = 420 . . . (3)
(2) - (3) => 4.75y = 180
y = 180 / 4.75 = 38
x = 60 - 38 = 22
Therefore, he should bicycle 22 minutes at 11 mph and 38 minutes at 15 mph.