NEED HELP ASAP PLEASE HELP What is 4.2 x 10-5 in standard notation?
O A. 420,000
O B.
1
4.25
O C. 0.000042
O D. 0.00042

Choice C) 0.000042

There are four zeros between the decimal point and the 4.

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Explanation:

The exponent -5 means we move the decimal point five spaces to the left to go from 4.2 to 0.000042

If the exponent was positive 5, then we would move the decimal point five spaces to the right.

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240

the diver is 33 feet below the surface.

step-by-step explanation:

hope this