(16×1/4 - 1 3/7)² ÷ 1/2= Срочно надо прошу помогите и пожалуйста по действиям

(16 * 1/4 - 1 3/7)² : 1/2 = 13 11/49
1) 16 * 1/4 = 16/4 = 4
2) 4 - 1 3/7 = 3 7/7 - 1 3/7 = 2 4/7
3) (2 4/7)² = (18/7)² = (18 * 18) / (7 * 7) = 324/49 = 6 30/49
4) 6 30/49 ÷ 1/2 = 6 30/49 × 2 = 648/49 = 13 11/49

$(16 * \frac{1}{4} - 1 \frac{3}{7})^{2} : \frac{1}{2} = 13 \frac{11}{49}$
$1) 16 * \frac{1}{4} = \frac{16}{4} = 4$
$2) 4 - 1 \frac{3}{7} = 3 \frac{7}{7} - 1 \frac{3}{7} = 2 \frac{4}{7}$
$3) (2 \frac{4}{7})^{2} = (\frac{18}{7})^{2} = \frac{18 * 18}{7 * 7} = \frac{324}{49} = 6 \frac{30}{49}$
$4) 6 \frac{30}{49} : \frac{1}{2} = 6 \frac{30}{49} * 2 = \frac{648}{49} = 13 \frac{11}{49}$