Answer: To eliminate the y terms and solve for x with minimum steps, we should multiply the first equation by 9 and the second equation by -4.
Step-by-step explanation:
Given: Equation (1) 5x − 4y = 28
Equation (2) 3x - 9y = 30
To eliminate the y-terms and determine x in the fewest operations, it requires us to multiply equation (1) by 9 and equation (2) by -4 to have
9(5x − 4y) =9 (28) ⇒ 45x - 36y = 252
-4(3x - 9y) = -4(30) ⇒ -12x + 36y = -120
By adding both equations together, the y-term is eliminated, leading to 45x - 12x = 132
⇒ 33x = 132 ⇒ x = 4.
