Đáp án: giải denta (40/x-6)+ (40/x+12)= (80/x) - Gặp mấy bài như này nếu không phân tích được mẫu thì đành quy đồng bỏ mẫu thôi =)) Bài làm Đkxd x khác 6 ; 0 ; -12 (40/x-6) + (40/x+12) = (80/x) ⇔ (40x(x+12)+40x(x-6)/x(x-6)(x+12)) = (80(x-6)(x+12)/x(x-6)(x+12)) ⇒ 40x(x+12)+40x(x-6) = 80(x-6)(x+12) ⇔ 40x^2 + 480x + 40x^2 - 240x = 80 ( x^2 + 12x -...

Gặp mấy bài như này nếu không phân tích được mẫu thì đành quy đồng bỏ mẫu thôi =)) Bài làm Đkxd x khác 6 ; 0 ; -12 (40/x-6) + (40/x+12) = (80/x) ⇔ (40x(x+12)+40x(x-6)/x(x-6)(x+12)) = (80(x-6)(x+12)/x(x-6)(x+12)) ⇒ 40x(x+12)+40x(x-6) = 80(x-6)(x+12) ⇔ 40x^2 + 480x + 40x^2 - 240x = 80 ( x^2 + 12x -...

王一博

4 tháng trước

giải denta $\frac{40}{x-6}$ + $\frac{40}{x+12}$ = $\frac{80}{x}$

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hoangbesttop2006

4 tháng trước

Gặp mấy bài như này nếu không phân tích được mẫu thì đành quy đồng bỏ mẫu thôi =))

Bài làm : Đkxd : x khác 6 ; 0 ; -12

$\frac{40}{x-6}$ + $\frac{40}{x+12}$ = $\frac{80}{x}$

⇔ $\frac{40x(x+12)+40x(x-6)}{x(x-6)(x+12)}$ = $\frac{80(x-6)(x+12)}{x(x-6)(x+12)}$

⇒ 40x(x+12)+40x(x-6) = 80(x-6)(x+12)

⇔ $40x^2$ + 480x + $40x^2$ - 240x = 80 ( $x^2$ + 12x - 6x - 72 )

⇔ $80x^2$ + 240x = 80 ( $x^2$ + 6x - 72 )

⇔ $80x^2$ + 240x - $80x^2$ - 480x + 5760 = 0

⇔ -240x + 5760 = 0

⇔ x = 24 ( thỏa mãn )

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giải denta 40x−6\frac{40}{x-6}+ 40x+12\frac{40}{x+12}= 80x\frac{80}{x}

1 câu trả lời

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Choose the best answer.
I think you should buy ___ pack of mineral water instead. And you can also buy _ snacks such as potato crisps, 3 kilos of mandarins, 2 kilos of apples, 3 bunches of bananas, ____ cookies and soft candies.

Choose the best answer.
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Choose the best answer.
I think that ______ cauliflower is not enough for 3 people. Let’s buy one more.