Đáp án:
$\text{Câu 1 : }$
$\text{ 4 . 125 . 3+ 2 . 35 + 12 . 40 }$
$\text{= 1500 + 70 + 480 }$
$\text{= 2050 }$
$\text{Câu 2 : }$
$\text{ x - 32 : 16 = 48 }$
$\text{⇔ x - 2 = 48 }$
$\text{⇔ x =48 + 2 }$
$\text{⇔ x = 50 }$
$\text{Vậy x = 50 }$
$\text{Câu 3 : }$
$\text{5x - 3x = 12 }$
$\text{⇔ 2x = 12 }$
$\text{⇔ x= 12 : 2}$
$\text{⇔ x = 6 }$
$\text{Vậy x = 6 }$
$\text{Câu 4 : }$
$\text{2 . (x-3) = 168 }$
$\text{⇔ x -3 = 168 : 2 }$
$\text{⇔ x - 3= 84 }$
$\text{⇔ x= 84 + 3 }$
$\text{⇔x = 87 }$
$\text{Vậy x = 87 }$