Divide both sides by 2 for the first one.
2c/2>2/2
c>1
simplify both sides for the second 1
1/6d>=1
6*(1/6d).=(6)*(1)
d>=6
For the last one
subtract 9 from both sides
r+9-9<=23-9 so that r<=14
Hope this helps!
Answer:
first one:
Area of a circle = π*r²
diameter (they gave) = 30ft
radius = diameter/2 = 15ft
π*15²= 706.85834705770347865409476123789
to nearest tenth= 706.9 ft
second question:
circumference = 2*π*r or d(diameter)*π
diameter = 30ft
30*π = circumference = 94.247779607693797153879301498385
in terms of π = 30π
Assuming simple interest (i.e. no compounding within first year), then
At 6%, interest = 10000*0.06=$600
At 9% interest = 10000*0.09 = $900
Two ways to find the ratio
method A. let x=proportion at 6%
then
600x+900(1-x)=684
Expand and solve
300x=900-684=216
x=216/300=0.72 or 72%
So 10000*0.72=7200 were invested at 6%
10000-7200=2800 were invested at 9%
method B: by proportions
Ratio of investments at 6% and 9%
= 900-684 : 684-600
=216 : 84
= 18 : 7
Amount invested at 6% = 18/(18+7) * 10000 = 0.72*10000 = 7200
Amount invested at 8% = 7/(18+7)*10000=0.28*10000=2800
12A + 2 + A - 1 = a + 12a + 1 = 13a + 1
