Toán Lớp 7: |7/5x + 2/3| = |4/3x -1/4| NHANH PLSSSSS

Question

Toán Lớp 7:  |7/5x + 2/3| = |4/3x -1/4| NHANH PLSSSSS

thanoanghha · Answer

|7/5x+2/3|=|4/3x-1/4|   =>  ( left[  begin{array}{l} dfrac{7}{5}x+ dfrac{2}{3}=-( dfrac{4}{3}x- dfrac{1}{4})   dfrac{7}{5}x+ dfrac{2}{3}= dfrac{4}{3}x- dfrac{1}{4} end{array}  right. )    =>  ( left[  begin{array}{l} dfrac{7}{5}x- dfrac{4}{3}x= dfrac{-2}{3}- dfrac{1}{4}   dfrac{7}{5}+ dfrac{2}{3}=- dfrac{4}{3}x+ dfrac{1}{4} end{array}  right. )    =>  ( left[  begin{array}{l} dfrac{1}{15}x= dfrac{-11}{12}   dfrac{7}{5}x+ dfrac{4}{3}x= dfrac{-2}{3}+ dfrac{1}{4} end{array}  right. )    =>  ( left[  begin{array}{l}x=- dfrac{55}{4}   dfrac{41}{15}x= dfrac{-5}{12} end{array}  right. )    =>  ( left[  begin{array}{l}x=- dfrac{55}{4}  x=- dfrac{25}{164} end{array}  right. )    Vậy x=- 55/4 hoặc x=- 25/164

lanthuhoa · Answer

Giải đáp: x in {-(55)/4;-(25)/(164)} Lời giải và giải thích chi tiết: | 7/5 x +2/3| = | 4/3 x -1/4| TH1: 7/5 x +2/3 = 4/3 x -1/4 <=> 12.7 x+ 20.2 = 20.4 x - 15 <=> 84 x +40 = 80x -15 <=> 84x -80x = -40-15 <=> 4x = -55 <=> x = -(55)/4 TH2: 7/5 x +2/3 = -(4/3 x -1/4) <=> 7/5 x +2/3 = -4/3 x +1/4 <=> 12.7 x + 20.2 = -20.4 x +15 <=> 84 x +40 = -80x +15 <=> 84x +80x = -40 +15 <=> 164x = -25 <=> x = -(25)/(164) Vậy x in {-(55)/4;-(25)/(164)}