Toán Lớp 7: giúp mình với 3.(5x+2/3) ²= 4/3

Question

Toán Lớp 7:  giúp mình với  3.(5x+2/3) ²= 4/3

baoquyen · Answer

Giải đáp + Lời giải và giải thích chi tiết:     3(5x+(2)/(3))^{2}=(4)/(3)   =>(5x+(2)/(3))^{2}=(4)/(3):3   =>(5x+(2)/(3))^{2}=(4)/(9)   =>  ( left[  begin{array}{l}5x+ dfrac{2}{3}= dfrac{2}{3}  5x+ dfrac{2}{3}=- dfrac{2}{3} end{array}  right. )    =>  ( left[  begin{array}{l}5x=0  5x=- dfrac{4}{3} end{array}  right. )    =>  ( left[  begin{array}{l}x=0  x=- dfrac{4}{15} end{array}  right. )    Vậy x&isin;{0;-(4)/(15)}

tuyetanhthu · Answer

3( 5x + 2/3)^2 = 4/3   => (5x+2/3)^2 = 4/3 : 3   =>(5x+2/3)^2 = 4/3 . 1/3   => (5x + 2/3)^2 = 4/9   +) (5x+2/3)^2 = (-2/3)^2   => 5x + 2/3 = -2/3   => 5x = -2/3 - 2/3   => 5x =-4/3   => x=- 4/3 : 5   => x= -4/3 . 1/5   => x=-4/15   +) (5x+2/3)^2 = (2/3)^2   => 5x + 2/3 = 2/3   => 5x =2/3 - 2/3   => 5x=0   =>x=0   Vậy x=0 hoặc x= -4/15