Police use the function ​f(x)=\sqrt{20} to estimate the speed of a​ car, f(x), in miles per​ hour, based on the​ length, x, in feet of its skid marks upon sudden braking on a dry asphalt road. A motorist is involved in an accident. A police officer measures the​ car's skid marks to be 84.05 feet long. Estimate the speed at which the motorist was traveling before braking. If the posted speed limit is 50 miles per​ hour, and the motorist tells the officer he was not​ speeding, should the officer believe​ him? Please help me

d, x=8

step-by-step explanation:

simplifying

4x + -5 = 2x + 11

reorder the terms:

-5 + 4x = 2x + 11

reorder the terms:

-5 + 4x = 11 + 2x

solving

-5 + 4x = 11 + 2x

solving for variable 'x'.

move all terms containing x to the left, all other terms to the right.

add '-2x' to each side of the equation.

-5 + 4x + -2x = 11 + 2x + -2x

combine like terms: 4x + -2x = 2x

-5 + 2x = 11 + 2x + -2x

combine like terms: 2x + -2x = 0

-5 + 2x = 11 + 0

-5 + 2x = 11

add '5' to each side of the equation.

-5 + 5 + 2x = 11 + 5

combine like terms: -5 + 5 = 0

0 + 2x = 11 + 5

2x = 11 + 5

combine like terms: 11 + 5 = 16

2x = 16

divide each side by '2'.

step-by-step explanation:

the true ones are a b and d

m

step-by-step explanation: