17)
4(x-1)² + 2 = 10
4(x-1)² = 8
(x-1)² = 2
|x-1| = √2
x - 1 = -√2 OR x - 1 = √2
x = 1-√2 OR x = 1 + √2
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19)
1/2 r² - 10 = 3/2 r²
-10 = 3/2 r² - 1/2 r²
-10 = r²
|r| = √(-10) (or no solution if you don't accept complex solutions)
r = √(-10) OR r = -√(-10)
r = i√10 OR r = -i√10
