Tìm x a) 15 - 3x = 6 b) 325 -(x + 5) = 125 c) 215 : x - 7 = 223 d) (x - 3) - 125 = 179 e) 125 - 28 = 73 f) 28 + 175 = 78

$\text{Tìm x:}$ $\\$ ${a,}$ ${15}$ ${-}$ ${3x}$ ${=}$ ${6}$ $\\$ ${3}$ ${.}$ ${x}$ ${=}$ ${15}$ ${-}$ ${6}$ $\\$ ${3}$ ${.}$ ${x}$ ${=}$ ${9}$ $\\$ ${x}$ ${=}$ ${9}$ ${:}$ ${3}$ $\\$ ${x}$ ${=}$ ${3}$ $\\$ $\text{b, 325 - (x + 5) = 125}$ $\\$ $\text{x + 5 = 325 - 125}$ $\\$ $\text{x + 5 = 200}$ $\\$ $\text{x = 200 - 5}$ $\\$ $\text{x = 195}$ $\\$ $\text{c, 215 : x - 7 = 223}$ $\\$ $\text{215 : x = 223 + 7}$ $\\$ $\text{215 : x = 230}$ $\\$ $\text{x = 215 : 230}$ $\\$ $\text{x = $\dfrac{43}{46}$}$ $\\$ $\text{Vì không chia được nên mình để dưới dạng phân số nhé.}$ $\\$ $\text{d, (x - 3) - 125 = 179}$ $\\$ $\text{x - 3 = 179 + 125}$ $\\$ $\text{x - 3 = 304}$ $\\$ $\text{x = 304 + 3}$ $\\$ $\text{x = 307}$