To eliminate one of the variables the coefficients have to have the same values but different signs.One has to be positive and one has to be negative then you could add them up to get become zero. So in the two systems of equations you can multiply the down equation by -6 to eliminate the y variable but the top equation will have to be the same.
-6(4x + y)=30(-6)
-24x -6y = -180
You can now rewrite the equation as
12x + 6y = 120
-24x -6y = -180 Now you can add the top and down equations to eliminate the y variable.
You can multiply the 2nd equation by either -3 or -6
Step-by-step explanation:
If you are using elimination (imo substitution on this problem would be easier), then you need to eliminate <em>one </em>of the variables. If you are wanting to eliminate x first, then multiply by -3. If you want to eliminate y first, then multiply by -6.
I recommend using a calculator, but working out the problem manually is alright too. Be sure to check your answer to make sure it's correct by looking over your work or by multiplying two of the numbers to see if it equals the third. The answer is about .92.
