Part a derek has $80 to spend on used books. hardcover books cost $10 each, and paperbacks cost $20 each. complete the equation which determines the number x of hardcover books and the number y of paperback books he can buy. x + y = part b for the situation in part a, which of the following represent possible combinations of books that derek can buy? select all that apply. a. (0, 4) b. (2, 3) c. (7, 2) d. (8, 0)

Options A , B and D are fulfilling the requirements.

Step-by-step explanation:

Derek has $80 to spend on used books. Hardcover books cost $10 each, and paperbacks cost $20 each.

Let x be the number of hardcover books and y be the number of paperback books Derek can buy.

The total books he can buy are

A.  (0, 4) substituting x as 0 and y as 4

= 80

B.  (2, 3) substituting x as 2 and y as 3

=

= 80

C.  (7, 2)  substituting x as 7 and y as 2

=

= 110

D.  (8, 0)  substituting x as 8 and y as 0

= 80

Hence, options A , B and D are fulfilling the requirements.

a28=58

step-by-step explanation:

a1=a1+(n-1)d

a28= 4+ (28-1)2

a28=4+(27)(2)

a28=4+54

a28=58

mrbilldoesmath!

answer: a parabola

steps:

(x-1)(x+4)   = x(x+4) - 1(x+4) = (x^2 + 4x) - (x+4)

                = x^2 +4x -x -4   = x^2 +3x -4

which is a parabola

mrb