Fungsi f dinyatakan dengn rumus f(x)=ax+b jika f(-5)=15 dan f(5)=-5 nilai dari f(1)

f(x) = ax + b

f(-5) = -5a + b
15 = -5a + b

f(5) = 5a + b
-5 = 5a + b

eliminasi b
-5a + b = 15
5a + b = -5
________-
-10a = 20
a = 20 : -10
a = -2

substitusi a = -2 ke persamaan 5a + b = -5
5(-2) + b = -5
b = -5 + 10
b = 5

fungsinya f(x) = -2x + 5

ditanyakan f(1) = -2(1) + 5 = -2 + 5 = 3