Question

seja f(x)=ax+b uma função linear. sabe-Se que f(-1)=5 e f(2)=7. Dê o valor de d(8)

Answer 1

f(-1)=5
f(2)=7

f(-1)=-1a+b=5
f(2)=2a+b=7


-a+b=5
2a+b=7


-2a+2b=10
2a+b=7
________
0+3b=17
b=17/3

-a+b=5
-a+17/3=5
-3a/3+17/3=15/3
-3a=15-17
-3a=-2
a=-2/-3
a=2/3

f(x)=2/3x+17/3
f(8)=2/3.8+17/3
f(8)=16/3+17/3
f(8)=33/3
f(8)=11