a,5x + 15 = 0 b,105 – 5x = 0 c, 3x + 7 = 0 đ, 0,3 – 1,2 = 0 15/08/2021 Bởi Abigail a,5x + 15 = 0 b,105 – 5x = 0 c, 3x + 7 = 0 đ, 0,3 – 1,2 = 0
a) 5x+15=0 `<=>`x=$\frac{0-15}{5}$ `=>`x=-3 b) 105-5x=0 `<=>` x=$\frac{105-0}{5}$ `=>`x=21 c) 3x + 7 = 0 `<=>`x=$\frac{0-7}{3}$ `=>`x≈2.3333 d) 0,3 – 1,2 = 0 (đề có sai ko) Bình luận
\( a)5x+15=0\\↔5x=-15\\↔x=-3\\Vậy\,\,S=\{-3\}\\b)105-5x=0\\↔5x=105\\↔x=21\\Vậy\,\,S=\{21\}\\c) 3x+7=0\\↔3x=-7\\↔x=-\dfrac{7}{3}\\Vậy\,\,S=\{-\dfrac{7}{3}\}\\d)Sai\) Bình luận
a) 5x+15=0
`<=>`x=$\frac{0-15}{5}$
`=>`x=-3
b) 105-5x=0
`<=>` x=$\frac{105-0}{5}$
`=>`x=21
c) 3x + 7 = 0
`<=>`x=$\frac{0-7}{3}$
`=>`x≈2.3333
d) 0,3 – 1,2 = 0
(đề có sai ko)
\( a)5x+15=0\\↔5x=-15\\↔x=-3\\Vậy\,\,S=\{-3\}\\b)105-5x=0\\↔5x=105\\↔x=21\\Vậy\,\,S=\{21\}\\c) 3x+7=0\\↔3x=-7\\↔x=-\dfrac{7}{3}\\Vậy\,\,S=\{-\dfrac{7}{3}\}\\d)Sai\)