Answer:
-144a^6 + 49x^2
Step-by-step explanation:
(12a^3 - 7x)(-12a^3 - 7x) =
Factor -1 out of the second binomial.
= (12a^3 - 7x)(-1)(12a^3 + 7x)
= -(12a^3 - 7x)(12a^3 + 7x)
After the first negative sign, you have the product of a sum and a difference:
(a + b)(a - b) = a^2 - b^2
= -(144a^6 - 49x^2)
Now, distribute the negative sign.
= -144a^6 + 49x^2
