Question

Tìm số tự nhiên \(x\), biết :

a) \(2.x-138=2^3.2^2\)

b) \(231-\left(x-6\right)=1339:13\)

Answer 1

a, \(2.x-138=2^3.2^2\\ =>2.x=\left(2^3.2^2\right)+138=32+138=170\\ =>x=170:2=85\)

b, \(231-\left(x-6\right)=1339:13\\ =>231-\left(x-6\right)=103\\ =>x-6=231-103=128\\ =>x=128+6=134\)

Answer 2

a) 2.x - 138 = 2³ . 2²

2.x - 138 = 2⁵

2.x - 138 = 32

2.x = 32 + 138

2.x = 170

x = 170 : 2

x = 85

b) 231 - ( x - 6 ) = 1339 : 13

231 - ( x - 6 ) = 103

x - 6 = 231 - 103

x - 6 = 128

x = 128 + 6

x = 134