Question

gostaria de saber a conta armada ×2=99-10ײ ?

Answer 1

x² = 99 - 10x² 

x² + 10x² = 99
11x² = 99
x² = 99/11
x² = 9
x = +/- √9
x = +/- 3

x' = 3
x'' = -3

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