Question

dada a função f(x)= ax + b e sabendo-se que f(3) = 5 e f(-2) = -5 calcule f(1/2)

Answer 1

f(3)=5                f(-2)=-5
a*5+b=5             a*(-2)+b=-5
 por sistema
5a+b=5
-2a+b=-5 *(-1)

5a+b=5
2a-b=5
 7a=10
a=7/10     
2(7/10)-b=5
14/10-b=5
-b=5-14/10
mmc
-b=36/10
b=-36/10

f(1/2) = 
7/10 * (1/2) -36/10
7/20-36/10
mmc
7-72/20
f(1/2) =  -65/20 (/5)=  -13/4