For the following system, if you isolated x in the first equation to use the Substitution Method, what expression would you substitute into the second equation?

-x - 2y = -4
3x + y = 12

Question

For the following system, if you isolated x in the first equation to use the Substitution Method, what expression would you substitute into the second equation?

-x - 2y = -4
3x + y = 12

radar · Answer

Step 1.  multiply first equation by -1 getting: x+2y = 4
Step 2.  Subtract 2y from both sides of equation getting: x=4-2y
x is now isolated.
Step 3. substitute in second equation for x this:  4-2y  that is all they are asking for.

anonymous · Answer

thanks