Answer:
A) f(0) = -7
B) f(-3) = 44
C) x = -1, (7/5)
Explanation:
2. Let f(x) = 5x² - 2x - 7.
(a) find f(0)
f(x) = 5x² - 2x - 7
f(0) = 5(0)² - 2(0) - 7
f(0) = -7
(b) find f(-3)
f(x) = 5x² - 2x - 7
f(-3) = 5(-3)² - 2(-3) - 7
f(-3) = 5(9) - 2(-3) - 7
f(-3) = 45 + 6 - 7
f(-3) = 45 + 6 - 7
f(-3) = 44
(c) find x if f(x) = 0
f(x) = 5x² - 2x - 7
f(x) = 5x² - 2x - 7 = 0
(5x² + 5x)(-7x - 7)
5x(x + 1) -7(x + 1)
(5x - 7)(x + 1)
5x - 7 = 0, x + 1 = 0
+7 +7 -1 -1
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5x = 7 x = -1
÷5 ÷5
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x = (7/5)
5(-1)² - 2(-1) - 7 = 0
5(7/5)² - 2(7/5) - 7 = 0
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I hope this helps!