làm hết và nhanh thưởng 5 sao ạ
1 trả lời
35 Tham khảo câu trả lời từ Trợ lý ảo Lazi Dưới đây là lời giải cho các phương trình từ câu 13 đến câu 36: ### Giải phương trình **13)** \( 2x - \frac{1}{2} = -5 \) - \( 2x = -5 + \frac{1}{2} \) - \( 2x = -\frac{10}{2} + \frac{1}{2} = -\frac{9}{2} \) - \( x = -\frac{9}{4} \) **14)** \( 2x - \frac{1}{3} = -\frac{4}{9} \) - \( 2x = -\frac{4}{9} + \frac{1}{3} = -\frac{4}{9} + \frac{3}{9} = -\frac{1}{9} \) - \( x = -\frac{1}{18} \) **15)** \( 3x - \frac{3}{5} = -7 \) - \( 3x = -7 + \frac{3}{5} = -\frac{35}{5} + \frac{3}{5} = -\frac{32}{5} \) - \( x = -\frac{32}{15} \) **16)** \( \frac{1}{2} + \frac{2}{3}x = \frac{4}{5} \) - \( \frac{2}{3}x = \frac{4}{5} - \frac{1}{2} = \frac{8}{10} - \frac{5}{10} = \frac{3}{10} \) - \( x = \frac{3}{10} \times \frac{3}{2} = \frac{9}{20} \) **17)** \( \frac{3}{4} + \frac{5}{2}x = 7 \) - \( \frac{5}{2}x = 7 - \frac{3}{4} = 7 - \frac{3}{4} \) - \( \frac{5}{2}x = \frac{28}{4} - \frac{3}{4} = \frac{25}{4} \) - \( x = \frac{25}{4} \times \frac{2}{5} = \frac{25}{10} = \frac{5}{2} \) **18)** \( \frac{5}{7}x - \frac{2}{3} = \frac{3}{10} \) - \( \frac{5}{7}x = \frac{3}{10} + \frac{2}{3} \) - Tìm mẫu số chung = 30: - \( = \frac{9}{30} + \frac{20}{30} = \frac{29}{30} \) - \( x = \frac{29}{30} \times \frac{7}{5} = \frac{29 \times 7}{150} = \frac{203}{150} \) **19)** \( \frac{3}{4} + x = -5 \) - \( x = -5 - \frac{3}{4} = -\frac{20}{4} - \frac{3}{4} = -\frac{23}{4} \) **20)** \( \frac{4}{5} + x = -\frac{1}{2} \) - \( x = -\frac{1}{2} - \frac{4}{5} = -\frac{5}{10} - \frac{8}{10} = -\frac{13}{10} \) **21)** \( \frac{3}{5}x = \frac{2}{7} \) - \( x = \frac{2}{7} \times \frac{5}{3} = \frac{10}{21} \) **22)** \( \frac{5}{2} - \frac{2}{3}x = 1 \) - \( -\frac{2}{3}x = 1 - \frac{5}{2} = -\frac{3}{2} \) - \( x = -\frac{3}{2} \times -\frac{3}{2} = \frac{9}{4} \) **23)** \( \frac{2}{3}x - \frac{4}{5} = -\frac{1}{2} \) - \( \frac{2}{3}x = -\frac{1}{2} + \frac{4}{5} = -\frac{5}{10} + \frac{8}{10} = \frac{3}{10} \) - \( x = \frac{3}{10} \times \frac{3}{2} = \frac{9}{20} \) **24)** \( \frac{4}{5} + \frac{1}{3}x = -1 \) - \( \frac{1}{3}x = -1 - \frac{4}{5} = -\frac{5}{5} - \frac{4}{5} = -\frac{9}{5} \) - \( x = -\frac{9}{5} \times 3 = -\frac{27}{5} \) **25)** \( \frac{2}{1} - \frac{5}{3}x = 1 \) - \( -\frac{5}{3}x = 1 - 2 = -1 \) - \( x = -1 \times -\frac{3}{5} = \frac{3}{5} \) **26)** \( \frac{4}{5}x + 2 = 2 \) - \( \frac{4}{5}x = 0 \) - \( x = 0 \) **27)** \( \frac{2}{3}x + 2 = \frac{5}{5} \) - \( \frac{2}{3}x = \frac{5}{5} - 2 = \frac{5}{5} - \frac{10}{5} = -\frac{5}{5} \) - \( x = -\frac{5}{5} \times \frac{3}{2} = -\frac{15}{10} = -\frac{3}{2} \) **28)** \( \frac{3}{4}x - \frac{1}{3} = -1 \) - \( \frac{3}{4}x = -1 + \frac{1}{3} = -\frac{3}{3} + \frac{1}{3} = -\frac{2}{3} \) - \( x = -\frac{2}{3} \times \frac{4}{3} = -\frac{8}{9} \) **29)** \( \frac{5}{4}x = 2 \) - \( x = 2 \times \frac{4}{5} = \frac{8}{5} \) **30)** \( \frac{2}{3}x = \frac{3}{4} \) - \( x = \frac{3}{4} \times \frac{3}{2} = \frac{9}{8} \) **31)** \( \frac{1}{7} + \frac{3}{7}x = \frac{3}{14} \) - \( \frac{3}{7}x = \frac{3}{14} - \frac{1}{7} = \frac{3}{14} - \frac{2}{14} = \frac{1}{14} \) - \( x = \frac{1}{14} \times \frac{7}{3} = \frac{1}{6} \) **32)** \( \frac{11}{5} + x = \frac{3}{4} \) - \( x = \frac{3}{4} - \frac{11}{5} \) - \( = \frac{15}{20} - \frac{44}{20} = -\frac{29}{20} \) **33)** \( \frac{1}{2} + \frac{1}{3}x = -1 \) - \( \frac{1}{3}x = -1 - \frac{1}{2} = -\frac{3}{2} \) - \( x = -\frac{3}{2} \times 3 = -\frac{9}{2} \) **34)** \( \frac{3}{4} + \frac{1}{6}x = 2 \) - \( \frac{1}{6}x = 2 - \frac{3}{4} = \frac{8}{4} - \frac{3}{4} = \frac{5}{4} \) - \( x = \frac{5}{4} \times 6 = \frac{30}{4} = \frac{15}{2} \) **35)** \( -\frac{5}{6} + x = 2 \) - \( x = 2 + \frac{5}{6} = \frac{12}{6} + \frac{5}{6} = \frac{17}{6} \) **36)** \( -\frac{1}{4} + \frac{3}{6}x = \frac{11}{36} \) - \( \frac{3}{6}x = \frac{11}{36} + \frac{9}{36} = \frac{20}{36} \) - \( x = \frac{20}{36} \times \frac{6}{3} = \frac{40}{36} = \frac{10}{9} \) Nếu cần thêm sự trợ giúp hoặc giải thích, hãy cho tôi biết nhé!