Step-by-step explanation:
Recall that

Therefore,

so


Answer: where’s the photo/attachment??
Step-by-step explanation:
Let

, where

and let

be any real constant.
Given this definition of scalar multiplication, we can see right away that there is no identity element

such that

because
(12x + 9y) + (-2y) - (4x - 3y)
= 12x + 9y - 2y - 4x + 3y
= 12x - 4x + 9y - 2y + 3y
= 8x + 10y
A) 8x + 10y
The first car consumed 21 gallons while the second car consumed 49 gallons. here is the how it's done.
for the first car gallons consumed is 15/50x70= 21 gallons
the second car consumed 35/50x70=49 gallons