Speed = distance / time => time = distance / speed
speed = 3x10^8 x 60 = 180x10^8 m per minute
time = 1.5x10^11/180x10^8 = 150x10^9/180x10^8 = 5/6x10 = 8,3 minutes
Answer: 100
Step-by-step explanation:
" · " - times
" + " - sum
n - a number
0.5n - half a number
10 · (0.5n + 6) = 8 |use distributive property
(10)(0.5n) + (10)(6) = 8
5n + 60 = 8 |substract 60 from both sides
5n = -52 |divide both sides by 5
n = -10.4
D.
first, eliminate B and C, because the highest degree in these two equation is 3, a 3-degree equation has 3 roots, not 4.
between A and D, A has the roots 0, 0, 7, and -7, all real roots.
D can be factored into (x²-49)(x²+1)=0
x²=49 or x²=-1
x=7 or -7, x=i or -i two real roots, two unreal roots
for the second equation:
first, find the first term by using the formula:
the nth term=the first term + (n-1)*difference
you are given the 13th term and d=3.7
a13=a1+(13-1)d
1.9=a1+12*3.7
a1=-42.5
the sum of the first 13 terms is S=(a1+a13)*(13/2)=(-42.5+1.9)*6.5=-263.9
Answer: 8:30, 16:60, 32:120
