Hey there!
-3x(4x + 3) + 5x
= -3x(4x) + -3x(3) + 5x
= -3x(4x) - 3x(3) + 5x
= -3x(4x) + 3(-3x) + 5x
= -12x^2 + 3(-3x) + 5x
= -12x^2 - 9x + 5x
= -12x^2 - 4
Therefore, your answer is: -12x^2 - 4
Good luck on your assignment & enjoy your day!
~Amphitrite1040:)