For every 1 litre of water used to make a medicine, 200 ml of sucrose and 300ml of saline
solution are used. Express the amount of water, sucrose and saline solution needed as a ratio
in its simplest form.

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

< 4 = < 5 they are vertical angles

120 degrees