Question

15+5x{20-5:[2-15:(18-3)]x4+15}+15

Answer 1

$\displaystyle \it 15+5 \times \{20-5:[2-15:(18-3)] \times 4+15\}+15= \\ =15+5 \times [20-5:(2-15:15) \times 4+15]+15= \\ =15+5 \times [20-5:(2-1) \times 4+15]+15= \\ =15+5 \times (20-5:1 \times 4+15)+15= \\ =15+5 \times(20-5 \times 4+15)+15= \\ =15+5 \times (20-20+15)+15= \\ =15+5 \times (0+15)+15= \\ =15+5 \times 15+15= \\ =15+75+15= \\ =90+15= \\ =105$