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Đáp án:
1/ x = 9
2/ x = 7
3/ x = 3
4/ x = 12
5/ x = 3
6/ x không thỏa mãn
7/ x = 1
8/ x = 3
9/ x = 9
10/ x = 9
Giải thích các bước giải:
1/ 2^4 . x – 3.5x = 5^2 – 2^4
=> 16.x – 3.5x = 25 – 16
=> 16.x – 15.x = 9
=> x = 9
2/ 3^2.x + 2^2.x = 26.2^2 – 13
=> 9.x + 4.x = 26.4 – 13
=> 13.x = 91
=> x = 91 : 13 = 7
3/ 5^2 . x – 2^4 . x= 3^4 – 6.3^2
=> 25.x – 16.x = 3^2 . 3^2 – 6.3^2
=> 9.x = 3^2(3^2 – 6)
=> 9 .x = 9.(9 – 6)
=> 9.x = 9.3
=> x = 3
4/ 7^2.x – 14x = 7^2.10 – 70
=> 49.x – 14.x = 49.10 – 70
=> 35.x = 490 – 70
=> 35.x = 420
=> x = 12
5/ 6^2.x – 5^2.x = 11.2^2 – 11
=> 36.x – 25.x = 11.4 – 11
=> 11.x = 11(4 – 1)
=> 11.x = 11.3
=> x = 3
6/ 7^2 . x + 6^2.x = 13.2^3 – 26
=> 49.x + 36.x = 13.8 – 26
=> 85.x = 78
=> x = 78/85
Mà x là số tự nhiên => x không thỏa mãn
7/ 2^3 . x + 5^2 . x = 2(5^2 + 2^3) – 33
=> 8.x + 25.x = 2.33 – 33
=> 33.x = 33(2 – 1)
=> 33.x = 33.1
=> x = 1
8/ 15 : (x + 2) = (3^3 + 3) : 10
=> 15 : (x + 2) = (27 + 3) : 10
=> 15 : (x + 2) = 3
=> x + 2 = 5
=> x = 3
9 / 20 : (x + 1) = (5^2 + 1) : 13
=> 20 : (x + 1) = (25 + 1) : 13
=> 20 : (x + 1) = 2
=> x + 1 = 10
=> x = 10 – 1 = 9
10/ 320 : (x – 1) = (5^3 – 5^2) : 4 + 15
=> 320 : (x – 1) = (125 – 25) : 4 + 15
=> 320 : (x – 1) = 100 : 4 + 15 = 40
=> x – 1 = 320 : 40
=> x – 1 = 8
=> x = 9