Help PLZ.
Which step could you use to start solving the system of equations below?
x + y = 3
-3x - 2y = -7
Group of answer choices
A. Multiply -3x - 2y = -7 by 2 and subtract it from x + y = 3
B. All of the above.
C. Multiply x + y = 3 by 3 and add it to -3x - 2y = -7
D. Add x + y = 3 to -3x - 2y = -7
Simplest way would be to multiply the first by 2, then add
Should be able to do it in your head
-x = -1
x = 1
mentally into first: y = 2
To start solving the system of equations x + y = 3 and -3x - 2y = -7, you can use the method of elimination. This involves manipulating the equations so that when they are added or subtracted, one of the variables cancels out.
Looking at the given answer choices:
A. Multiply -3x - 2y = -7 by 2 and subtract it from x + y = 3: This is incorrect because multiplying -3x - 2y = -7 by 2 and subtracting it from x + y = 3 does not help eliminate any variables.
B. All of the above: This cannot be the correct answer because A and C contradict each other.
C. Multiply x + y = 3 by 3 and add it to -3x - 2y = -7: This is the correct choice. Multiplying x + y = 3 by 3 gives you 3x + 3y = 9, and then adding it to -3x - 2y = -7 eliminates the variable x when you add the equations together, leaving you with 3y - 2y = 9 - 7.
D. Add x + y = 3 to -3x - 2y = -7: This is incorrect because adding x + y = 3 to -3x - 2y = -7 does not eliminate any variables.
Therefore, the correct answer is C. Multiply x + y = 3 by 3 and add it to -3x - 2y = -7.