Answer:
m = 8
Explanation:
Expand the left side
Each term in the second factor is multiplied by each term in the first factor
7a²(4a² - 1) + 2a(4a² - 1) - 3(4a² - 1) ← distribute parenthesis
= 28
- 7a² + 8a³ - 2a - 12a² + 3 ← collect like terms
= 28
+ 8a³ - 19a² - 2a + 3
Comparing the coefficients of like terms with those on the right , then
m = 8