Answer:

Step-by-step explanation:
So we have the system:

If we isolate the x-variable in the first equation:

Subtract 2y from both sides:

Divide both sides by -1:

Therefore, we would substitute the above into the second equation:

The answer is 2y+6
Further notes:
To solve for the system, distribute:

Simplify:

Subtract:

Divide:

Now, substitute this value back into the isolated equation:

Answer:
4x+7 = 5x-20
(reason: vertical angles are congruent; property used: distributive)
7 = 1x-20
1x = 7+20
1x = 27
x = 27
The correct choice is the third one. Y=2/3x
Answer:
x=-5
Step-by-step explanation:
25 - 3x = 40
-3x + 25 =40
-3x +25--25=40-25
-3x=15
-3x÷-3=25÷-3
x=-5