A variable needs to be eliminated to solve the system of equations below Choose the correct first step. 3x+7y=68 3x-y=4 Answer Add to eliminate x. Subtract to eliminate y. Subtract to eliminate x. Add to eliminate y.

To solve the system of equations, we need to eliminate one of the variables. In this case, we can eliminate the variable x by subtracting the second equation from the first equation.<br /><br />Subtracting the second equation from the first equation gives us:<br /><br />$3x + 7y - (3x - y) = 68 - 4$<br /><br />Simplifying this equation gives us:<br /><br />$8y = 64$<br /><br />Dividing both sides by 8 gives us:<br /><br />$y = 8$<br /><br />Now that we have the value of y, we can substitute it back into either of the original equations to solve for x. Let's use the second equation:<br /><br />$3x - y = 4$<br /><br />Substituting y = 8 into this equation gives us:<br /><br />$3x - 8 = 4$<br /><br />Adding 8 to both sides gives us:<br /><br />$3x = 12$<br /><br />Dividing both sides by 3 gives us:<br /><br />$x = 4$<br /><br />Therefore, the solution to the system of equations is x = 4 and y = 8.