A pen cost half as much as a ruler. Write an expression to describe how much the pen cost, using r as the cost of the ruler.​

r=2p

Step-by-step explanation:

If r is ruler and p is pen, ruler equals pen times 2, so its r=2p

y do u put "subscirbe to ence" on a app for ppl who need with their work?

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