Its 89 because 9 times 2 is 81 and 10 times 2 is 100 there nothing to multiple 2 by something to get 89
Answer:
9.09
Step-by-step explanation:
x=speed of boat
y=speed of water current
Downstream relative speed = x+y
Upstream relative speed = x-y
Distance remains the same for both upstream and downstream.
a) Distance travelled downstream = speed x time = 3(x+y)
Distance travelled upstream = speed x time = 3.6(x-y)
b) Since both distances are equal, we can write
3(x+y)= 3.6(x-y)
3x+3y = 3.6x-3.6y
6.6y = 0,6x
x=11y: y=x/11
c) Water current has speed as 1/11 times of that of boat
In percent this equals 100/11 = 9.09%
Answer:
B
Step-by-step explanation:
The circumference is just diameter x π (3.14 in this case) so 42 x 3.14 = 131.88
X²-9x=36
minus 36 both sides
x²-9x-36=0
what 2 numbers multiply to -36 and add to -9
-12 and 3
(x-12)(x+3)=0
set to zero
x-12=0
x=12
x+3=0
x=-3
the number is either -3 or 12