Question

bài 1: thực hiện phép tính

1) (13.17\(^4\)+4.17\(^4\)):17\(^3\)-(14.\(3^3\)-14.3\(^2\)):9

2) \(2^3\).\(5^2\)-[131-(23-2\(^3\))\(^2\)]

bài 2: tìm x

1) 6\(^2\).x+14.x-3\(^4\)=69

2) 3\(^x\)=81

3) 3. (2x+1)\(^2\)=75

Answer 1

2:

1: =>36x+14x=69+81=150

=>50x=150

=>x=3

2: 3^x=81

=>3^x=3^4

=>x=4

3: 3(2x+1)^2=75

=>(2x+1)^2=25

=>2x+1=5 hoặc 2x+1=-5

=>x=-3 hoặc x=2

1:

1: \(\dfrac{13\cdot17^4+4\cdot17^4}{17^3}-\dfrac{14\cdot3^3-14\cdot3^2}{9}\)

\(=\dfrac{17^4\cdot\left(13+4\right)}{17^3}-\dfrac{14\cdot3^2\left(3-1\right)}{9}\)

\(=17\cdot17-14\cdot2\)

=289-28

=261

2:

\(2^3\cdot5^2-\left[131-\left(23-2^3\right)^2\right]\)

\(=8\cdot25-131+\left(-1\right)^2\)

=69+1

=70