CPhill

1000*30,000 = 30,000,000

36x^2-121=0   factor as a difference of squares

(6x + 11) (6x - 11)  = 0

Set each factor to 0

6x + 11  = 0                                           6x - 11  = 0

Subtract 11 from both sides                  Add 11 to both sides

6x  = -11                                                 6x  = 11

                     Divide both sides by 6

x =  -11/6                or                        x =  11/6

The radius can't be determined without knowing the arc length spanned by the central angle of 150°

Thanks, Ninja   ....here's another approach

We have to multiply the first term by the constant ratio - call it, r -  twice to get to the third term....this means that :

875 / 35  = r^2

25  = r^2      take the positive/neg sq root of both sides

±5 = r

So, either r = 5 or r = -5.....

Then the second term is either   35 * 5  = 175

Or the second term is  35 * - 5  =  -175

And the second must be correct.....so.....the common ratio =  -5   and the answer is "d"

The pentagon is composed of 5 congreunt isosceles triangles....

We can find  the length of one of the equal sides of one of these triangles, thusly

x / sin90  = 4/ sin(54)    where x is one of the equal sides of an isosceles triangle

So  x =  4/sin(54)

And using trig.....the total area is given by:

5(1/2) (4/sin(54))^2 * sin(72)  = about  58.12 cm^2  =  "A"

d^2 = (30)^2+(33)^2-2(30)(33)(cos(115))

d^2  = 900 + 1089  - 1980cos(115)

d^2 = 1989 - 1980cos(115)     take the positive square root of both sides

d = sqrt [ 1989 - 1980cos(115) ]   = about 2825.8

2-5x= - 18    subtract 2 from both sides

-5x = -20       divide both sides by -5

x = -20/-5   = 4

The percentage is given by :

( [770/700  - 1]   X 100 )%  =   

( [11/10  - 1] X 100 )%  =

([1/10] x 100)%  =

10%

Sin  A =  3/5  = y/r

Tan A  = y/x  = 3/x

And we can find x thusly :

x = sqrt (r^2  - y^2)  =  sqrt (5^2   - 3^2)  = sqrt (25 - 9)  = sqrt (16)  = 4

So.....

Tan A   =  y/x  =  3/4

Circumference  =   2 * pi * radius     or    pi * diameter