10 Given f(x)=2x find: a f(a) b f(a+2) f(4a) d 4f(a)

a) $f(a) = 2a$<br /><br />b) $f(a+2) = 2(a+2) = 2a + 4$<br /><br />c) $f(4a) = 2(4a) = 8a$<br /><br />d) $4f(a) = 4(2a) = 8a$