Question

Suppose that the functions S and T are define for all real numbers x as follow.

s(x)=x-3
t(x)=3x+1

Write the expressions for (s-t)(x)and (s.t)(x) and evaluate (s+t(-2)

Answer 1

(s-t) = (x-3)-(3x+1) = -2x-4
(s.t) = (x-3)(3x+1)
(s+t)(-2) = s(-2)+t(-2) = -5 + -5 = -10
or,
(s+t)(x) = (x-3)+(3x+1) = 4x-2
so (s+2)(-2) = 4(-2)-2 = -10