Toán Lớp 6: Bài 1: Tìm x: a,-49-5x=-74 b,|x+(-62)|+(-13)=25 c,4x-48=-x+22 d,-8+75=2x-15

Question

Toán Lớp 6:  Bài 1: Tìm x: a,-49-5x=-74 b,|x+(-62)|+(-13)=25 c,4x-48=-x+22 d,-8+75=2x-15

daithanh · Answer

a. -49 - 5x = -74     5x = -49 - (-74)     5x = 25       x = 25 : 5       x = 5     Vậy x = 5     ___________________________     b. |x + (-62)| + (-13) = 25     |x + (-62)| = 25 - (-13)     |x + (-62)| = 38     => x + (-62) = 38 hoặc x + (-62) = 38     TH1 :     x + (-62) = 38                  x = 38 - (-62)                  x = 100     TH2 :     x + (-62) = -38                  x = - 38 - (-62) = -38 + 62                  x = 24     Vậy x = 100 ; x = 24     __________________________________________     c. 4x - 48 = -x + 22     4x - 48 + x = 22     4x + x = 22 + 48     5x = 70       x = 70 : 5       x = 14     Vậy x = 14     _________________________________     d. -8 + 75 = 2x - 15     67 = 2x - 15     67 + 15 = 2x     82 = 2x     x = 82 : 2     x = 41     Vậy x = 41

thanhtung · Answer

B&agrave;i 1:   a, -49 - 5x = -74     5x = -49 - (-74)     5x = -49 + 74     5x = 25     x = 25 : 5     x = 5   b, |x + (-62)| + (-13) = 25     |x + (-62)| = 25 + 13     |x + (-62)| = 38   Ta c&oacute;:   TH1: x + (-62) = 38           x = 38 + 62           x = 100   TH2: x + (-62) = -38           x = -38 + 62           x = 24   Vậy x = 100 hoặc x = 24   c, 4x - 48 = -x + 22     4x + x = 48 + 22     5x = 70     x = 70 : 5     x = 14   Vậy x = 14   d, -8 + 75 = 2x - 15     67 = 2x - 15     2x - 15 = 67      2x = 67 + 15     2x = 82     x = 82 : 2     x = 41   Vậy x = 41