Which equation can replace 3x 5y = 59 in the original system and still produce the same solution? 2x – y = –4 10x – 5y = –20 7x = 39 13x = 39

From my research, the original system of equations contain the following equations:

2x − y = −4 
3x + 5y = 59

where obtained solution is x = 3

Among the choices, it is easier to substitute 3x + 5y = 59 with one of the choices to see if they yield the same solution set. From trial-and-error, the equation that can replace the original equation is " 13x = 39 ". Among the choices, it is the 4th choice.

First one is 1 second one is 3