To solve a three-variable system of equations, you can use a combination of the elimination and substitution mehtods.

true or false

It is true that in order to solve a three-variable system of equations, you can use a combination of the elimination and substitution methods.
This is the best way to solve these kinds of equations, as you get rid of the unnecessary variables. 

Answer d; a supplementary angle = 180°, so if that angle = 150°, y would = 30°.