Which expression represents a positive number? A. 1/5 divided by -4/7 B.-1/5 divided by 4/7 C. -1/5 divided by -4/7 D. 1/5 divided by 4/-7

c

Step-by-step explanation:

remember,

a positive number multiplied or divided by a negative number = negative

a negative number multiplied or divided by a positive number = negative

a positive number multiplied or divided by a positive number = positve

a negative number multiplied or divided by a negative number = positive

so, if you have two numbers of the same sign being multiplied or divided, the answer will always be positive. if you have two numbers of different signs, the answer will always be negative.

within the answer choices, c is the only option where both numbers are negative, which means that if those two negative numbers are divided, you will get a positive answer.

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.