Final answer:
To simplify the expression 5(x - 12x^2) + 3(4x + 7x^2), distribute the coefficients and then combine like terms to get 17x - 39x^2.
Step-by-step explanation:
To simplify the expression 5(x - 12x2) + 3(4x + 7x2), we need to distribute the coefficients to each term inside the parentheses and then combine like terms.
First, distribute 5 to (x - 12x2) which gives us 5x - 60x2.
Next, distribute 3 to (4x + 7x2) which gives us 12x + 21x2.
Finally, combine the like terms 5x and 12x to get 17x, and -60x2 and 21x2 to get -39x2. So the simplified expression is 17x - 39x2.