Question

simplify and evaluate if X=-1,y=2
3xy (2x+7y-5)-7x(xy-y²+9)-3​

Answer 1

$3xy(2x + 7y - 5) - 7x(xy - {y}^{2} + 9) - 3 \\ 3 \times - 1 \times 2(2 \times - 1 + 7 \times 2 - 5) - 7 \times - 1( - 1 \times 2 - {2}^{2} + 9) - 3 \\ - 6( - 2 + 14 - 5) + 7( - 2 - 4 + 9) - 3 \\ - 6(7) + 7(3) - 3 \\ = - 42 + 21 - 3 \\ - 45 + 21 \\ = - 24$