Renata wins a $20 gift card to an online music site. after renata purchases 16 songs, the gift card has a remaining balance of $0. which equation represents the relationship between y, the remaining balance on renata’s gift card, and x, the number of songs purchased? 4x + 5y = –100 5x + 4y = 80 4x + 5y = 16 5x + 4y = 20

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.

y -5 = (-1/4)(x + 8)

step-by-step explanation: