Question

[nguyễn thu trang]

1) 3(x-5)(2x+9)+3x-15=0

2) (x²-16)(12-4x)=0

3) (9-x²)(4x-8)=0

4) (8-x³)(5^x-125)=0

5) 4^x=8

Answer 1

[Nguyễn Ngọc Chi]

1)=>3(x-5)(2x+9)+3(x-5)=0=>(x-5)(6x+30)

=>x-5=0=>x=5

6x+30=0=>x=-5

2)=>x^2-16=0=>x=+-4

12-4x=0=>x=3

3)=>9-x^2=0=>x=+-3

4x-8=0=>x=2

4)=>8-x^3=0=>x=3

5^x-125=0=>x=2

5)=>2^x.2^x=8=>2^2x=8=>2x=3=>x=1,5

Answer 2

[Nguyễn Ngọc Chi]

tick mk với