Answer:
a) Add 4 to both sides, and then divide by 2. The solution is
.
Step-by-step explanation:
Question:
Which of the following describes the correct process for solving the equation 2x − 4 = 20 and arrives at the correct solution?
a) Add 4 to both sides, and then divide by 2. The solution is x = 12.
b) Divide both sides by −4, and then subtract 2. The solution is x = −7.
c) Subtract 4 from both sides, and then divide by 2. The solution is x = −12.
d) Multiply both sides by −4, and then divide by 2. The solution is x = −40.
Solution:
Given equation:

We need to determine the steps in order to solve for
.
Solving for
.
Step 1: Adding 4 both sides.


Step 2: Dividing both sides by 2.

∴ 
Thus, we added 4 both sides and then divided both sides by 2 to get solution = 12
First find x and y.
Solve system of equations by elimination.
3x-y=3
+(-x+y=3)
---------------
2x=6
x=3
Now plug in x into one of the equations to find y.
-3+y=3
y=6
xy=3x6=18