Toán Lớp 8: Giải phương trình: 3(5x-2)/4 -2=7x/3 -5(x-7)
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Toán Lớp 8: Giải phương trình: 3(5x-2)/4 -2=7x/3 -5(x-7)
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(3(5x-2))/4 – 2=(7x)/3-5(x-7)
<=> 9(5x-2)-24 = 28x – 60(x-7)
<=> 45x-18-24=28x-60x+420
<=> 45x-28x+60x=18+24+420
<=>77x=462
<=>x=6
Vậy S={6}
[3.(5x – 2)]/(4) – 2 = (7x)/3 – 5.(x-7)
<=> ( 15x – 6 )/4 – (7x)/3 = 2 – 5x + 35
<=> [ 3.(15x – 6) – (7.4)x ]/12 = 37 – 5x
<=> 45x – 18 – 28x = 12. (37 – 5x)
<=> 45x – 28x + 60x = 12.37 + 18
<=> 17x + 60x = 444 + 18
<=> 77x = 462
<=> x = 6
Vậy phương trình có nghiệm: S = {6}.