I need help with these I forgot how to solve them​

Step-by-step explanation:

if x = 7 and y = 4

a) x + 2y

= 7 + 2 . 4

= 7 + 8

= 15

b) (2x - y)/5

= (2 . 7 - 4)/5

= (14 - 4)/5

= 10/5

= 2

The first equation is 15 and the second equation is 2.

Step-by-step explanation:

You have to use substitution. For the first equation it would be: 7 + 2(4),which is 7 + 8,which is 15. For the second equation it would be: 2(7) - 4 divided by 5,which is also 14 - 4 divided by 5,which is 10/5, which is 2.

a and c

step-by-step explanation: