Nicholas Mak's answer to Isabella's Secondary 4 A Maths question.

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Nicholas Mak
Nicholas Mak's answer
16 answers (A Helpful Person)
1st
With 3 unknowns, you need to eliminate one first (z) before using your usual elimination method to find 2 unknowns (x and y in this case). Once x and y is found, use them to find z