d ) 3 mũ x – 1 = 2 mũ 4.5 g ) ( x – 1) mũ 2 =25 h ) 6 . x mũ 3 – 8 = 40

2 bình luận về “d ) 3 mũ x – 1 = 2 mũ 4.5 g ) ( x – 1) mũ 2 =25 h ) 6 . x mũ 3 – 8 = 40”

1. d)

   3^(x)-1=2^(4).5

   =>3^(x)-1=16.5

   =>3^(x)-1=80

   =>3^(x)=81

   =>3^x=3^4

   =>x=4

   Vậy x=4

   g)

   (x-1)^2=25

   =>(x-1)^2=(+-5)^2

   =>$[\begin{array}{l}x-1=5\\ x-1=-5\end{array}$

   =>$[\begin{array}{l}x=6\\ x=-4\end{array}$

   Vậy x in {6;-4}

   h)

   6.x^(3)-8=40

   =>6.x^3=40+8

   =>6.x^3=48

   =>x^3=48:6

   =>x^3=8

   =>x^3=2^3

   =>x=2

   Vậy x=2

   Trả lời
2. d)

   3^x – 1 = 2^4 . 5

   3^x – 1 = 80

   3^x = 80 + 1

   3^x = 81

   3^x = 3^4

   => x = 4

   g)

   (x-1)^2=25

   (x-1)^2=5^2

   x-1=5

   x=5+1

   x=6

   => x = 6

   (x-1)^2=25

   (x-1)^2=(-5)^2

   x-1=-5

   x=-5+1

   x=-4

   => x = -4

   Vậy x in {6 ; -4}

   h)

   6 . x^3 – 8 = 40

   6 . x^3 = 40 + 8

   6 . x^3 = 48

   x^3 = 48:6

   x^3 = 8

   x^3 = 2^3

   => x = 2

   Trả lời