Question

If r(x) = 3x − 1 and t(x) = −4x − 1, find (r + t)(7).

9

−9

−49

49

Answer 1

plug and chug

Answer 2

r(x) is the same thing as r.... only diff is it is in terms of x
[(3x - 1) + (-4x -1) ] * 7

Answer 3

-49?

Answer 4

no... it just means add the two functions together...:
(r+t)(7) = r(7) + t(7) = (3*7 - 1) + (-4*7 - 1) = (20) + (-29) = -9

consequently, you can also simplify (r+t)(x) an calculate from there:
(r+t)(x) = (3x-1) + (-4x-1) = -x - 2

so (r+t)(x) = -(7) - 2 = -9