Answer:
(a) = 26.4 or (132/5); 0
(b) = 26.4 or (132/5); -220
(c) = 0; -220
(d) = 0
Explanation:
-5k²- 22k + 15
(a)
-5( -3/5 )² - 22( -3/5 ) + 15
-1.8 + 13.2 + 15 = 26.4 or
(-9/5) + (66/5) + 15 = (132/5)
I don't know if you do decimal points or fractions so I did both.
-5( -5 )² - 22( -5 ) + 15
-125 + 110 + 15 = 0
(b) -5 ( -3/5 )²- 22( -3/5 ) + 15
-1.8 + 13.2 + 15 = 26.4 or
(-9/5) + (66/5) + 15 = (132/5)
-5 ( 5 )²- 22( 5 ) + 15
-125 - 110 + 15 = -220
(c)
-5 ( 3/5 )²- 22( 3/5 ) + 15
-1.8 - 13.2 + 15 = 0 or
(-9/5) - (66/5) + 15 = 0
-5 ( 5 )²- 22( 5 ) + 15
-125 - 110 + 15 = -220
(d)
-5 ( 3/5 )²- 22( 3/5 ) + 15
-1.8 - 13.2 + 15 = 0 or
(-9/5) - (66/5) + 15 = 0
-5( -5 )² - 22( -5 ) + 15
-125 + 110 + 15 = 0
I hope this helps!