The Richter scale measures the magnitude, M, of an earthquake as a function of its intensity, I, and the intensity of a reference earthquake, . Which equation could be used to find the intensity of an earthquake with a Richter scale magnitude of 4.8 in reference to an earthquake with an intensity of 1? A. B. C. D.

The equation is = I =

Step-by-step explanation:

As given ,

M - magnitude of an earthquake

I - intensity of earthquake

I₀ - intensity of a reference earthquake

The relation between the three is as follows :

M = log( )

As given -

M = 4.8,  I₀ = 1

⇒ 4.8 = log() = log(I)

⇒ 4.8 = log(I)

⇒I =

So, the equation becomes I =

one that is bigger than 3 1/2

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18