Answer:
(8, -4)
Step-by-step explanation:
26. 1/2
27. 1/4
28. 25
29. 20
x=4
x^3-4x^2-16x+64
(x^2-16)(x-4)
x-4=0
+4 +4
x^2-16=0
+16 +16
x^2=16
√ x^2=√ 16