7x + y = 13 4x – 4y = -20
2 answers:
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Answer:
x = ± 15
Step-by-step explanation:
Given f(x) = - 0.5x² and f(x) = - 112.5 , then equate right sides
- 0.5x² = - 112.5 ( divide both sides by - 0.5 )
x² = 225 ( take square root of both sides )
x = ± = ± 15