Step-by-step explanation:
Part A:
4x² - 7x - 15
a, b, c = 4, -7, -15
ac = -60
factors that add up to -7 and multiply to -60 are (-12, 5)
rewrite equation
(4x² - 12x) + (5x - 15)
factor out GCF from both groups
4x(x - 3) + 5(x - 3)
(4x+5)(x-3)
Part B:
Using the factored form from the previous part we can set both factors equal to 0 to solve for x.
4x+5 = 0
4x = -5
x = -5/4
x-3 = 0
x = 3
the two x-intercepts are -5/4 and 3
Part C:
Since the leading coefficient is positive, the right side of the function will be going up or to positive infinity as x goes towards positive infinity. Since the degree is even both sides go in the same direction so on the left side it also goes towards positive infinity as x goes towards negative infinity.
