9. (X + 0,7)^3 = -27
10. ( 2/3x -1/3)^5 = 1/243
11. ( (2/5-3X)^2 = 9/25
12. (2x-1)^10 = 49^5
13. X : 5^2 = (3/5)^2 : 3^2
9. (X + 0,7)^3 = -27 10. ( 2/3x -1/3)^5 = 1/243 11. ( (2/5-3X)^2 = 9/25 12. (2x-1)^10 = 49^5 13. X : 5^2 = (3/5)^2 : 3^2
By Harper
Đáp án + Giải thích các bước giải:
9)
`(x+0,7)^3=-27`
`=>x+0,7=-3`
`=>x=-3,7`
10)
`(2/3x-1/3)^5=1/243`
`=>2/3x-1/3=1/3`
`=>2/3x=2/3`
`=>x=1`
11)
`(2/5-3x)^2=9/25`
`=>2/5-3x=3/5` hoặc `2/5-3x=-3/5`
`=>3x=-1/5` hoặc `3x=1`
`=>x=-1/15` hoặc `x=1/3`
Vậy `x∈{-1/15;1/3}`
12)
`(2x-1)^10=49^5`
`=>(2x-1)^10=(7^2)^5`
`=>(2x-1)^10=7^10`
`=>2x-1=7`
`=>2x=8`
`=>x=4`
13)
`x:5^2=(3/5)^2:3^2`
`=>x:25=9/25:9`
`=>x:25=1/25`
`=>x=1`
9. `(x+0,7)^3 = -27`
`(x+0,7)^3 = (-3)^3`
`⇒ x+0,7 = -3`
`⇒ x = -3,7`
10. `(2/3x – 1/3)^5 = 1/243`
` ( 2/3x -1/3)^5 = (1/3)^5`
`⇒ 2/3x – 1/3 = 1/3`
`⇒ 2/3x = 2/3`
`⇒ x = 1`
11. `(2/5-3X)^2 = 9/25`
`(2/5-3x)^2 = (3/5)^2`
`⇒ 2/5 – 3x = 3/5`
`⇒ 3x = -1/5`
`⇒ x = -1/15`
12. ` (2x-1)^10 = 49^5`
`⇒ (2x-1)^10 = (7^2)^5 = 7^10`
`⇒ 2x-1=7`
`⇒ 2x=8`
`⇒ x = 4`
13. `x : 5^2 = (3/5)^2 : 3^2`
`x : 5^2 = (3/5 : 3)^2`
`x:5^2 = 1/25`
`x = 1`