6+{50:[4×(8+x:5)-15]×6}:3=10
{50:[4×(8+x:5)-15]×6}:3 = 10 - 6
{50:[4×(8+x:5)-15]×6}:3 = 4
50:[4×(8+x:5)-15]×6 = 4 × 3
50:[4×(8+x:5)-15]×6 = 12
50:[4×(8+x:5)-15] = 12 : 6
50:[4×(8+x:5)-15] = 2
4×(8+x:5) - 15 = 50 : 2
4×(8+x:5) - 15 = 25
4×(8+x:5) = 25 + 15
4×(8+x:5) = 40
8+x : 5 = 40 : 4
8+x : 5 = 10
x : 5 = 10 - 8
x : 5 = 2
x = 2 × 5
x = 10
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