Question

Bài 2 (1,5 điểm): Tìm x:

a) 200 – 8.(2x + 7) = 112

b) (2x – 123):3 = 33

c) H = {x ∈ ℤ | -3 < x ≤ 3}

Answer 1

You có thể Tham khảo thêm :

a) 200 – 8.(2x + 7) = 112

-8.(2x + 7) = 112 – 200

-8.(2x + 7) = -88

2x + 7 = (-88):(-8)

2x + 7 = 11

2x = 11 – 7

2x = 4

x = 4:2

x = 2.

b) (2x – 123):3 = 33

2x – 123 = 33.3

2x – 123 = 99

2x = 99 + 123

2x = 222

x = 222:2

x = 111

c) H = {x ∈ ℤ | -3 < x ≤ 3}

Vì H = nên H = {-2; -1; 0; 1; 2; 3}

Vậy x ∈ {-2; -1; 0; 1; 2; 3}

Answer 2

a).

<=> 200 - 16x - 56 = 112

<=> 144 - 16x = 112

=> x = (144 - 112 ) : 16 = 2