Question

Tính x, biết

A) ( x + 49 ) - 115 =0

B) 125 . ( 2 x - 3 ) = 5⁵ : 5³

Answer 1

a) (x + 49) - 115 = 0

x + 49 = 0 + 115

x + 49 = 115

x = 115 - 49

x = 66

Vậy x = 66

b) 125 . (2x - 3) = 5⁵ : 5³

125 . (2x - 3) = 5² = 25

2x - 3 = 25 : 125

2x - 3 = 1/5

2x = 1/5 + 3

2x = 1/5 + 15/5

2x = 16/5

x = 16/5 : 2

x = 16/5 . 1/2

x = 8/5

Vậy x = 8/5

Answer 2

a) (x+49)-115=0

=>x+49=0+115=115

=>x=115-49=66

b)125.(2x-3)=5⁵:5³

=>125.(2x-3)=5²

=>125(2x-3)=25

=>2x-3=25:125

=>2x-3=\(\frac{1}{3}\)

=>2x=\(\frac{1}{3}\)+3

=>2x=\(\frac{10}{3}\)

=>x=\(\frac{10}{3}:2\)

=>x=\(\frac{5}{3}\)

Answer 3

a) (x+49)-115=0

=>x+49=0+115=115

=>x=115-49=66

b)125.(2x-3)=5⁵:5³

=>125.(2x-3)=5²

=>125(2x-3)=25

=>2x-3=25:125

=>2x-3=1/5

=>2x=1/5+3

=>2x=16/3

=>x=16/3:2

=>x=8/3