The sum of 48 and itself, its half and half of the half is added to 18.

150

Step-by-step explanation:

This is a word problem which should be tackled accordingly.

The sum of 48 and itself

= 48+48

= 96

It's half and half of its half

= 48/2 and (48/2)/2

= 24+ 24/2

= 24+12

= 36

Is added to 18

= 96+36+18

= 150

From the description above the entire sum is 150.

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18