He got too tired over work. A) because of

B) because off

C) on

D) for​

A

Explanation:

Off represents turning something off for example, like disabling something.

Of is more pointy to things and stuff.

Just find the pronunciation of these words and say sentences out loud to eliminate obvious wrong answers.

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4