Final answer:
The constant a that makes the function continuous on the entire real line is 16.
Step-by-step explanation:
To find the constant a such that the function f(x) is continuous on the entire real line, we need to ensure that the two parts of the function match at x = 1.
Therefore, we set the two expressions equal to each other and solve for a:
7x² = ax - 9
Substituting x = 1 into the equation:
7(1)² = a(1) - 9
7 = a - 9
a = 16
Thus, the constant a such that the function is continuous on the entire real line is a=16.