It would be 6 because 21 is 3 times as much to 7 so 2 times 3 is 6<span />
Not sure if there was supposed to be a list, but here is one expression that is equivalent. 2.2n+4. Since all I did was add like terms, I can come upon an equivalent expression.
substitute every x in the equation with (-2)
f(-2)=3*2*(-2) = -12
dunno if I get your equation correctly, pls check how you have written it
