if r(s) = (s+2)*2-4s. which statement is true?
A. r(2)=8
B. r(4)=18
C. r(-1)=-3
D. r(-10)=24
To find the value of r(s), we substitute s into the given expression:
r(s) = (s+2)*2-4s
A. To find r(2), we substitute s=2:
r(2) = (2+2)*2-4(2) = (4)*2 - 8 = 8 - 8 = 0
B. To find r(4), we substitute s=4:
r(4) = (4+2)*2-4(4) = (6)*2 - 16 = 12 - 16 = -4
C. To find r(-1), we substitute s=-1:
r(-1) = (-1+2)*2-4(-1) = (1)*2 + 4 = 2 + 4 = 6
D. To find r(-10), we substitute s=-10:
r(-10) = (-10+2)*2-4(-10) = (-8)*2 + 40 = -16 + 40 = 24
Therefore, the true statement is:
D. r(-10) = 24