Assume that children is an integer variable containing the number of children in a community and that families is an integer variable containing the number of families in the same community. write an expression whose value is the average number of children per family.

children / (double) families.

Step-by-step explanation:

Integer division returns an Integer value in most languages. I'm assuming "1d" is a double-precision 1, which turns the expression into a floating point division.

on friday there were 15 birds

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