Which answer shows 9 x 10 ^ -5 written in standard form ? A -0.000009
B -0.00009
C 0.0009
D 0.00009

  D  0.00009

Step-by-step explanation:

9 × 10^-5 = 9 × 1/10^5 = 9 × 1/100,000

  = 9 × 0.00001

  = 0.00009

Comment on place value

The exponent of 10 associated with the place value in a decimal number increases from 0 to the left of the decimal point, and decreases from -1 to the right of the decimal point:

  100. = 10²

  10. = 10¹

  1. = 10⁰

  0.1 = 10⁻¹

  0.01 = 10⁻²

  0.001 = 10⁻³

  0.0001 = 10⁻⁴

  0.00001 = 10⁻⁵

This simple realization can help you immensely with scientific notation.

x = ± 6i

step-by-step explanation:

x^2 = -36

take the square root of each side

sqrt(x^2) = sqrt(-36)

we know sqrt(ab) = sqrt(a) sqrt(b)

x = ±sqrt(36) sqrt(-1)

we know that sqrt (-1) = i

x = ± 6i

pay attention in your classes and concentrate the best thing you can do to raise your test scores is to pay attention when you're supposed to be learning the material: in class!

take good notes.

do your homework.

use mnemonics and other tricks.

do practice tests.

note: the best i know.