Answer:
Th correct option is (d).
Step-by-step explanation:
The given expression is :
[tex]16x^2 + nx + 49[/tex] ....(1)
We know that, 16 = 4² and 49 = 7²
Also, (a+b)² = a²+2ab+b²
The given expression becomes,
[tex]16x^2 + nx + 49=(4x)^2+nx+7^2\\\\=(4x)^2+2(4x)(7)+7^2\\\\=16x^2+56x+49\ ......(2)[/tex]
Comparing equations (1) and (2),
n = 56
Hence, the value of n is equal to 56.