(a) 7y(-4xy + 5) = (7y* -4xy) + (7y*5) = -28xy2 + 35y
(b) 7x(-4x + 5y) = (7x* -4x) + (7x*5y) = -28x2 + 35xy
(c) 7x(-4y + 5y) = (7x* -4y) + (7xx*5y) = -28xy + 35xy
(d) 7y(-4x + 5) = (7y* -4x) + (7y*5) = -28xy + 35y
So, the bottom-most option is the right answer.
