Respuesta :
Answer:
a) 7.2 b) 10.4 c) 3.4 d) 3.6
Step-by-step explanation:
f(x) = 3(x - 1) - 0.4(9 - x)
a) f(2) + f(4)
First we will need to find f(2). Substitute 2 for x
f(2) = 3(2 - 1) - 0.4(9 - 2)
Use the distributive property
f(2) = (6 - 3) - (3.6 - 0.8)
f(2) = 3 - 2.8
f(2) = 0.2
Now we need to find f(4). It is the same process as we need for f(2), except x = 4 here
f(4) = 3(4 - 1) - 0.4(9 - 4)
f(4) = (12 - 3) - (3.6 - 1.6)
f(4) = 9 - 2
f(4) = 7
Now we add both answers together:
f(2) + f(4)
0.2 + 7 = 7.2
f(2) + f(4) = 7.2
b) f(5)
f(5) = 3(5 - 1) - 0.4(9 - 5)
f(5) = (15 - 3) - (3.6 - 2)
f(5) = 12 - 1.6
f(5) = 10.4
c) f(7) - f(6)
f(7) = 3(7 - 1) - 0.4(9 - 7)
f(7) = (21 - 3) - (3.6 - 2.8)
f(7) = 18 - 0.8
f(7) = 17.2
f(6) = 3(6 - 1) - 0.4(9 - 6)
f(6) = (18 - 3) - (3.6 - 2.4)
f(6) = 15 - 1.2
f(6) = 13.8
f(7) - f(6)
17.2 - 13.8 = 3.4
f(7) - f(6) = 3.4
d) f(3)
f(3) = 3(3 - 1) - 0.4(9 - 3)
f(3) = (9 - 3) - (3.6 - 1.2)
f(3) = 6 - 2.4
f(3) = 3.6
