(2 phần 3 x + 1 phần 3 )^ 2 = 4 phần 9 giúp mình vs 05/07/2021 Bởi Cora (2 phần 3 x + 1 phần 3 )^ 2 = 4 phần 9 giúp mình vs
Đáp án: `(2/3x+1/3)^2=4/9` TH1: `(2/3x+1/3)^2=(2/3)^2` `⇔2/3x+1/3=2/3` `⇔2/3x=1/3` `⇔x=1/3.(3/2)` `⇔x=1/2` TH2: `(2/3x+1/3)^2=(-2/3)^2` `⇔2/3x+1/3=-2/3` `⇔2/3x=-1` `⇔x=-1.3/2` `⇔x=-3/2` vậy `x∈{1/2;-3/2}` Bình luận
Đáp án:
`(2/3x+1/3)^2=4/9`
TH1: `(2/3x+1/3)^2=(2/3)^2`
`⇔2/3x+1/3=2/3`
`⇔2/3x=1/3`
`⇔x=1/3.(3/2)`
`⇔x=1/2`
TH2: `(2/3x+1/3)^2=(-2/3)^2`
`⇔2/3x+1/3=-2/3`
`⇔2/3x=-1`
`⇔x=-1.3/2`
`⇔x=-3/2`
vậy `x∈{1/2;-3/2}`