( x-4) (3x -y)
multiply the first X with the other two terms in the other paranthesis
so x * 3x and x * -y
and ull get
3x^2 - xy
now multiply the -4 with the two terms of other paranthesis
so -4 * 3x and -4 * -y
and u get -12x and 4y
cant simpligly so
3x^2 - xy -12x + 4y