`a) 1230 : 3(x-20) = 10`
`=> 3(x-20) = 123`
`=> x - 20 = 41`
`=> x = 61`
`b) 250 - 10(24-3x):15=244`
`=> 10(24-3x):15 = 6`
`=> 10(24-3x) = 90`
`=> 24-3x = 9`
`=> 3x = 24 - 9`
`=> 3x = 15`
`=> x = 5`
`c) 4x^3 + 15 = 47`
`=> 4x^3 = 32`
`=> x^3 = 8`
`=> x^3 = 2^3`
`=> x = 2`
`d) 65 - 4^(x+2) = 2014^0`
`=> 65 - 4^(x+2) = 1`
`=> 4^(x+2) = 64`
`=> 4^(x+2) = 4^3`
`=> x + 2 = 3`
`=> x = 1`
`e) 4 . 2^x - 3 = 125`
`=> 4 . 2^x = 128`
`=> 2^x = 32`
`=> 2^x = 2^5`
`=> x = 5`
(Chúc bạn học tốt)
