Tyna simplified the expression StartFraction 3 x cubed Over 12 x Superscript negative 2 Baseline EndFraction to StartFraction x Over 4 EndFraction. What was Tyna's mistake? She divided the coefficients incorrectly. She added the exponents instead of subtracting them. She divided the coefficients instead of subtracting them. She subtracted the exponents instead of dividing them.

She divided the coefficients incorrectly

Step-by-step explanation:

A. She divided the coefficients incorrectly.

B. She added the exponents instead of subtracting them.

C. She divided the coefficients instead of subtracting them.

D. She subtracted the exponents instead of dividing them.

Correct calculation:

3x³/12x^-2

= 3x³ ÷ 12x^-2

= 3x³ ÷ 1/12x²

= 3x³ × 12x²/1

= 36x^5

Tyna's calculation:

3x³/12x^-2 = x/4

why do wages differ across industries

step-by-step explanation :

micro economists are concerned with economics on an industry or individual firm basis.

macro economists are concerned with national and international level