Pickles cost $8.99 each, watermelons cost $7.49 each. if I purchased 10 pickles and watermelons for $85.40, how much of each did I purchase? I WILL GIVE 15 POINTS.

7 pickles, 3 watermelons

Step-by-step explanation:

p = number of pickles purchased

w = number of watermelons purchased

p + w = 10

8.99p + 7.49w = 85.40

Multiply the first equation by 7.49

7.49p + 7.49w = 74.90

Subtract the new first equation from the second

(8.99p - 7.49p) + (7.49w - 7.49w) = 85.40 - 74.90

1.50p = 10.5

p = 10.5/1.5

p = 7

Substitute p into the first equation to find w

p + w = 10

7 + w = 10

w = 10 - 7

w = 3

Check it using the second equation

8.99(7) + 7.49(3) = 85.40

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.