(7y² + 6xy) - (-2xy + 3)
⇒ (-1 * -2xy) + (-1 * 3) = 2xy - 3
7y² + 6xy + 2xy - 3
7y² + 8xy - 3 Choice B.
For Q3, you can subsitute x = 2 and y = 5 into the systems
-5(2) + 5 = -5
so it's a solution for the first system
-4(2)+2(5) = 2
it's also a solution for the second system
