Đáp án + Giải thích các bước giải:
a, `3^2(x + 1) - 3 = 2^3 + (7^2 xx 2) : 14`
` 9(x + 1) - 3 = 8 + 14 xx 7 : 14`
` 9(x + 1) - 3 = 8 + 7`
` 9(x + 1) - 3 = 15`
` 9(x + 1) = 15 + 3`
` 9(x + 1) = 18`
` x + 1 = 18 : 9`
`x + 1 = 2`
` x = 2 - 1`
` x = 1`
Vậy `x = 1`
b, `2^2 xx 3(x + 5) - 6^2 = (2^3 + 2^2) xx 2^2`
` 4 xx 3(x + 5) - 36 = (8 + 4) xx 4`
` 12(x + 5) - 36 = 12 xx 4`
` 12(x + 5) - 36 = 48`
` 12(x + 5) = 48 + 36`
` 12(x + 5) = 84`
` x + 5 = 84 : 12`
` x + 5 = 7`
`x = 7 - 5`
`x = 2`
Vậy `x = 2`
c, `(2^2 + 1)(x + 14)= 5^2 xx 4 + (25 + 3^2 + 7^2) : 2`
` (4 + 1)(x + 14) = 25 xx 4 + (25 + 9 + 49) : 2`
` 5(x + 14) = 100 + 83/2`
` 5(x + 14) = 283/2`
` x + 14 = 283/2 : 5`
` x + 14 = 283/10`
` x = 283/10 - 14`
` x = 283/10 - 140/10`
` x = 143/10`
Vậy `x = 143/10`
d, `(2^2 - 1)(x - 1) = 2^2 + (6^2 + 2^6) : (5^2 xx 2)`
` (4 - 1)(x - 1) = 4 + (36 + 64) : (25 xx 2)`
` 3(x - 1) = 4 + 100 : 50`
` 3(x - 1) = 4 + 2`
` 3(x - 1) = 6`
` x - 1 = 6 : 3`
`x - 1 = 2`
`x = 2 + 1`
`x = 3`
Vậy `x = 3`
e, `(3^2 - 2)(x - 12) + 35 = 5^2 + 279 : 3^2`
`(9 - 2)(x - 12) + 35 = 25 + 279 : 9`
` 7(x - 12) + 35 = 25 + 31`
` 7(x - 12) + 35 = 56`
` 7(x - 12) = 56 - 35`
` 7(x - 12) = 21`
` x - 12 = 21 : 7`
` x - 12 = 3`
` x = 3 + 12`
`x = 15`
Vậy `x = 15`
