20) A pipe is at least 21 feet long, and must be cut into three pieces. The 2nd piece must be twice as long as the first piece, and the 3rd piece must be one foot longer than the second piece. Using an inequality, find the minimum length of the first piece.

it is b)

hope this : )

step-by-step explanation:

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.

the answer will be b x² +x-1

step-by-step explanation: