7-3=4 so that would be it and y= -7 or -3
You have 3 and 1.
You have 7 and 1.
-Take one number from the top and one number from the bottom.
-Pair them together and multiply them.
-There will be 2 numbers left unselected.
-Pair them together and multiply them.
-See if you can add them or subtract them to obtain 4
-If you can, place each paired number in an opposite bracket. You know which values are "stuck" to a so then you just need to work out the signs.