The price of an item has been reduced by 20%. The original price was $90. What is the price of the item now?
2 answers:
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Answer:
x = √2 + 2, -√2 + 2
Step-by-step explanation:
y = -2(x-2)² + 4
-2(x-2)² + 4 = 0 --- replace y with 0
-2(x - 2)² = -4 --- subtract 4 from both sides
(x - 2)² = --- divide both sides by -2
(x - 2)² = 2 --- simplify
x - 2 = +-√2 --- square root both sides
x - 2 = √2 --- split into 2 equations
x - 2 = -√2
x = √2 + 2 --- solve first equation
x = -√2 + 2 --- solve second equation
x = √2 + 2, -√2 + 2