19z-7 - ( 5z-9 + <span>8z+3)
= 19z - 7 - (13z - 6)
= 19z - 7 - 13z + 6
= 6z - 1
answer
remaining side = </span> 6z - 1
9 millimeters= 0.9 centimeters
800+16x=720+21x
80+16x=21x
80=5x
X=16
So 16 hours :)
P(t) = [ 64/ (1 + 11.e⁽⁻⁰ ⁰⁸t⁾]
In 1991, t = 1, hence:
P(t) = [ 64/ (1 + 11.e⁽⁻⁰ ⁰⁸ˣ¹⁾] = 5.7377 billion or rounded 5.74 billion
(Answer A)