Answer:
(d) 9x² -12y² -11x
Step-by-step explanation:
The sum of polynomials (8x² -9y² -4x) and (x² -3y² -7x) is found by combining like terms.
Polynomial addition
When simplifying the sum of polynomials, the distributive property comes into play. It lets you add and remove parentheses, recognizing that factors outside parentheses multiply each term inside parentheses.
(8x² -9y² -4x) + (x² -3y² -7x)
= 8x² -9y² -4x + x² -3y² -7x . . . . . eliminate parentheses
= (8 +1)x² +(-9 -3)y² +(-4 -7)x
= 9x² -12y² -11x
