Question

Answer 1

bài 4 
a) <=>x + 71 = 400 : 4
<=> x = 100 - 71
<=> x = 29
b) <=> x²⁰⁰ - x = 0
<=> x (x¹⁹⁹ -1) = 0
<=> x = 0 ; x = 1

Answer 2

`4.(x+71)=400`

`x+71=400:4`

`x+71=100`

`x=100-71`

`x=29`

____________________________________

`x^200 =x`

`x^200 - x = 0`
`x(x^199 - 1) = 0`

`=> x=0`

`=> x^199 - 1=0`

`x^199 = 0+1`

`x^199 = 1`

`=> x = 1`

Vậy `x={0;1}`