The question is in the picture.

arc CD = 160°

Step-by-step explanation:

The measures of the arcs on the circle = 360° , then

arc CD = 360 - AC - AD = 360 - 3x - 7x = 360 - 10x

--------------------------------------------------------------------------

The measure of the secant- tangent angle ABC is half the difference of the intercepted arcs, that is

(7x - 3x) = 40 ( multiply both sides by 2 to clear the fraction )

7x - 3x = 80

4x = 80 ( divide both sides by 4 )

x = 20

Then

CD = 360 - 10x = 360 - 10(20) = 360 - 200 = 160°

p> q if you calculate p is100 q is 79

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.