Toán Lớp 6: Bài 2: Tìm x, biết: a,3^2-3x=6^10:6^9 b, 3^x-5=2^2 c, (3x-2^4).7^10=2.7^11 d, 63-(5x-2):11=20

Question

Toán Lớp 6:  Bài 2: Tìm x, biết: a,3^2-3x=6^10:6^9 b, 3^x-5=2^2 c, (3x-2^4).7^10=2.7^11 d, 63-(5x-2):11=20

hiennhi98 · Answer

B&agrave;i l&agrave;m       B&agrave;i 2: T&igrave;m x, biết: a,3^2-3x=6^10:6^9      3^2 - 3x = 6                3x = 3^2 - 6                3x = 3                   x = 3 : 3                  x = 1 b, 3^x-5=2^2       3^x - 5 = 4                 3^x = 4 + 5                 3^x = 9                 3^2 = 9                 &rArr; x = 2 c, (3x-2^4).7^10=2.7^11       3x - 2^4  = 2.7^11 : 7^10        3x - 2^4 = 14                 3x = 14 + 2^4                 3x = 30                   x = 30 : 3                   x = 10 d, 63-(5x-2):11=20     d,63-(5x-2):11=20  (5x-2):11=43  5x-2=473  5x=475  x=95

cobelolen · Answer

a, 3^2-3x=6^10:6^9      9-3x=6    3(3-x)=6    3-x=2     x=1   b,3^x-5=2^2   3^x=4+5   3^x=3^2   x=2   c,(3x-2^4).7^10=2.7^11   3x-16=14   3x=30   x=10   d,63-(5x-2):11=20   (5x-2):11=43   5x-2=473   5x=475   x=95