An airplane company is determining the difference in selling price if rows of first-class seats are added to a new design. Using the average selling price of $1,000 per first-class seat, the total selling price for one new row is f(r) = 4,000r. Each row in first class eliminates two rows of economy seats. Using the average selling price of $150 per economy seat, the total price for each pair of removed rows is e(r) = 1,800r.

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.

homozygous. one is homozygous, while two is heterozygous.

hiking down a winding trail.

step-by-step explanation:

answer:   expression= p+p*d%

price reduction + sale price = $625

sale price: $p+$p*d%

where d% is the percentage of discount

step-by-step explanation:

original price = p

price went down by $150 price reduction $p*d%

sale price= $ 475

therefore the price before sale is: $625

and the expression that shows the price before sale is: p+p*d%