A smoothie recipe uses banana, kiwi and yoghurt in the ratio 4:1:3 by weight.
(a)
A smoothie is made using 280 g of banana.
How much kiwi and yoghurt are needed?

people went from manufacturing one object at a time by hand to manufacturing many objects in factories

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