Answer:
(x + 9) (x - 5)
Explanation:
The expression y = x² + 4x - 45 can be factorize as:
(x + a)(x + b)
Where a and b are two numbers such that the sum of them is equal to 4 and the product of them is equal to -45.
It means that the values of a and b are:
a = 9
b = -5
Because:
a + b = 4
9 + ( - 5) = 4
a*b = -45
9*(-5) = -45
So, the factorization of the expression is:
(x + 9) (x - 5)
Therefore, the equivalent expression to y = x² + 4x - 45 is:
(x + 9) (x - 5)
