Răspuns:
Explicatie pas cu pas:
a - b - 1 = 5
a - b = 5 + 1
a - b = 6
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n = - 3 × a + 19 + 3 × b
n = - 3 × a + 3 × b + 19
n = - 3 × ( a - b ) + 19
n = - 3 × 6 + 19
n = - 18 + 19
n = 1