Answer: the value of 7x-y is -14.
Step-by-step explanation:
When x=2 and y=4,
To find the value of 7x - y when x =2, y = 4, this means when ever you see x, put 2 in replacement, y, put 4 respectively.
7x - y = 7(2 - 4)
14 - 28
= -14.
