Răspuns:
[tex]a = \frac{2972}{3} [/tex]
Explicație pas cu pas:
[tex]((20 + 139 \div 3 + a \div 4) \times 7 - 5 \times 400) \div 3 - 22 \times 3 + 125 \times 8 = 1000 \\ [/tex]
[tex](( \frac{199}{3} + \frac{1}{4} a) \times 7 - 2000) \times \frac{1}{3} - 66 + 1000 = 1000 \\ [/tex]
[tex]( \frac{1393}{3} + \frac{7}{4} a - 2000) \times \frac{1}{3} - 66 + 1000 = 1000 \\ [/tex]
[tex]( - \frac{4607}{3} + \frac{7}{4} a) \times \frac{1}{3} - 66 + 1000 = 1000 \\ [/tex]
[tex] \frac{ - 18428 + 21a}{12} \times \frac{1}{3} - 66 + 1000 = 1000 \\ [/tex]
[tex] \frac{ - 18428 + 21a}{36} - 66 = 0 \\ [/tex]
[tex] - 18428 + 21a - 2376 = 0[/tex]
[tex] - 20804 + 21a = 0 [/tex]
[tex]21a = 20804[/tex]
[tex]a = \frac{20804}{21} [/tex]
[tex]\boxed{ a = \frac{2972}{3} }[/tex]
