On the number line below, the letters a and b are the same distance from 0. what is a + b?

The answer here would be 0.

Step-by-step explanation:

If a and b are both equal distances from 0, then adding the together would equal 0. Since a is the inverse of b,  using any number and its inverse will show you why the answer is 0. For example, if b is 9 then a would be -9. Adding these together equals 0.

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

18.75 gallons

step-by-step explanation: