Răspuns:
[tex]150 - [2 * [(a - 9): 8-3] + 9*7] * 2 = 8\\\\150 = 8 + [2 * [(a - 9): 8-3] + 9*7] * 2\\\\150 -8= [2 * [(a - 9): 8-3] + 9*7] * 2 \\\\142 =[2 * [(a - 9): 8-3] + 63] * 2 \:\:\:\:\: /:2\\\\ 71 = 2 * [(a - 9): 8-3] + 63 \\\\71-63 = 2 * [(a - 9): 8-3]\\\\ 8 = 2 * [(a - 9): 8-3]\:\:\:\:\: /:2\\\\ 4 = (a - 9): 8-3\\\\4+3 = (a - 9): 8\\\\7 = (a - 9): 8\:\:\:\:\: /*8\\\\56 = a-9\\\\56+9=a\\\\\boxed{a=65}[/tex]