exam Maths Puzzle Numerical Ability

Oh, please help me with this, I do NOT understand this system math....

Solve the following system by substitution.

4x - 2y = 8
2x + 4y =8

Read Solution (Total 0)

exam Other Question

Hi, i have some problem solving my Math assignment. Kindly help me to solve some of the problem and i need Solution and checkings. I really appreciate your help. Thank you!
1)Ther Mr.Nelson lost one of his students test papers. He knos thar thre other 4 students scored as follows: 12,20,21,12. He know that the average score is 19.4.What the score on the missing paper.