Answer:
x²-8x-1=0
comparing above equation with ax²+bx+c=0
a=1
b=-8
c=-1
x=

=(--8+-√(64-4×1×-1)/2×1
=8+-√(64+4)/2
taking positive
x=(8+√68)/2=2(4+√17)/2=4+√17
taking negative
x=(8-√68)/2=2(4-√17)/2=4-√17
(x-5)(x+3)=0
x^2+3x-5x-15=0
(x^2+3x) (-5x-15)
x(x+3) -5(x+3)
x-5=0 x+3=0
x=5 OR -3
Answer:
24
Step-by-step explanation:
4 years ago, Daniel would've been 4 and Kevin would be 20, so Kevin would've been 5 times as old as Daniel. And 8 x 3 = 24. So, Kevin is 24.
Answer:
3
Step-by-step explanation:
3 under each
The days she has recorded: 11 + 10 + 7 + 6 + 3 + 2 = 39
The mode distance (most often): 5 km
Median distance: 6.64 km ~= 6.5 km ~= 7 km by rounding upwards, so 3rd
Cumulative frequency: 11; 21; 28; 34; 37; 39