0.4x + 2.5 = 0.2x - 4

-30

Step-by-step explanation:

0,4x +2,5=0,2x - 4

0,4x - 0,2x =-4 - 2

0,2x =-6

x=-6 :0,2

x=-30

11 feet 6 inches and 8 feet 6 inches

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