f(x)=px+q, jikaf(-2)=-13 dan f(3)=12, maka nilai f(5) adalah

f(x) = px + q
f(-2) = -2p + q = -13
f(3) = 3p + q = 12

eliminasi q
-2p + q = -13
3p + q = 12 (dikurangi)
-5p. = -25
p = -25/-5
p = 5

substitusi p= 5
3.5 + q = 12
15 + q = 12
q = 12 - 15
q = -3

f(x) = 5p - 3
f(5) = 5.5 - 3 = 25 - 3 = 22

f(x) = px + q

f(-2) = p(-2) + q
-13 = -2p + q

f(3) = p(3) + q
12 = 3p + q

12 = 3p + q
-13 = -2p + q _
-------------------
25 = 5p
5 = p

12 = 3(5) + q
12 = 15 + q
12 - 15 = q
-3 = q

f(5) = 5(5) - 3
f(5) = 25 - 3
f(5) = 22