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nangsofia
2 năm trước

Giải phương trình: √(15 - x) + √(3 - x) = 6

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Lê Công Vinh
2 năm trước

Đáp án:

Giải thích các bước giải:

taihop60
2 năm trước

Đáp án:

Giải thích các bước giải:

ĐK -9=

$\sqrt{15-x} + \sqrt{3-x} =6$

$<=> 15-x+3-x+2\sqrt{(15-x)(3-x)} =36$

$<=>\sqrt{x^2-18x+45} =x+9$

$<=> x^2-18x+45=x^2+18x+81$

$<=>36x=-36$

$<=>x=-1 (TMĐK)$

Vậy$ x=-1$

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