Toán Lớp 7: -3/4+1/4:x=-2/5 |x+1/3|=3/4 (2x-1/2)^2=1/16 Tìm x

Question

Toán Lớp 7:  -3/4+1/4:x=-2/5 |x+1/3|=3/4 (2x-1/2)^2=1/16 Tìm x

hienthucthu97 · Answer

Bạn tham khảo &darr;

dananhnhu2k4 · Answer

frac{-3}{4} + 1/4 : x = frac{-2}{5}   1/4 : x = frac{-2}{5} - frac{-3}{4}   1/4 : x = frac{-2}{5} + 3/4   1/4 : x = frac{-8}{20} + 15/20   1/4 : x = 7/20   x = 1/4 : 7/20   x = 1/4 &middot; 20/7   x = 20/28   x = 5/7   Vậy x = 5/7   |x + 1/3| = 3/4   Ta c&oacute;:   TH1: x + 1/3 = 3/4           x = 3/4 - 1/3           x = 9/12 - 4/12           x = 5/12   TH2: x + 1/3 = frac{-3}{4}           x = frac{-3}{4} - 1/3           x = frac{-9}{12} - 4/12           x = frac{-9}{12} + frac{-4}{12}           x = frac{-13}{12}   Vậy x = 5/12 hoặc x = frac{-13}{12}   (2x - 1/2)^2 = 1/16   (2x - 1/2)^2 = (1/4)^2   TH1:   2x - 1/2 = 1/4   2x = 1/4 + 1/2   2x = 1/4 + 2/4   2x = 3/4   x = 3/4 : 2   x = 3/4 &middot; 1/2   x = 3/8   TH2:    2x - 1/2 = frac{-1}{4}   2x = frac{-1}{4} + 1/2   2x = frac{-1}{4} + 2/4   2x = 1/4   x = 1/4 : 2   x = 1/4 &middot; 1/2   x = 1/8   Vậy x = 3/8 hoặc x = 1/8