66% of the water consumption is industrial use and 33% is personal use so (66% - 33%) = 33% more water is used for industrial purposes. 20,000 gallons are consumed daily so industry consumes \( \frac{33}{100} \) x 20,000 gallons = 6,600 gallons.

To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so subtract the coefficients and retain the base and exponent:

-2a⁶ - 4a⁶
(-2 - 4)a⁶
-6a⁶

The commutative property states that, when adding or multiplying numbers, the order in which they're added or multiplied does not matter. For example, 3 + 4 and 4 + 3 give the same result, as do 3 x 4 and 4 x 3.

The distributive property for division helps in solving expressions like \({b + c \over a}\). It specifies that the result of dividing a fraction with multiple terms in the numerator and one term in the denominator can be obtained by dividing each term individually and then totaling the results: \({b + c \over a} = {b \over a} + {c \over a}\). For example, \({a^3 + 6a^2 \over a^2} = {a^3 \over a^2} + {6a^2 \over a^2} = a + 6\).

Latoya scored 81% on the test meaning she earned 81% of the possible points on the test. There were 240 possible points on the test so she earned 240 x 0.81 = 195 points. Each question is worth 3 points so she got \( \frac{195}{3} \) = 65 questions right.