Seven more than a number

a + 7?

Step-by-step explanation:

The number we are adding seven to is indefinite, so a variable would be in order. a represents the number being add and 7 is what is being added to a.

Hope this helps you somehow. Have a nice day!

45.3592

step-by-step explanation:

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