Question

Aflati valoarea numărului necunoscut a din: 12 • [(5•a-6):7+23]:4-15+3=63.​

Answer 1

Răspuns:

12×[(5×a-6):7+23]:4-15+3=63

$12( \frac{5a - 6}{7} + 23) \times \frac{1}{4} - 15 + 3 = 63$

$3 \times \frac{5a - 6 + 161}{7} - 15 + 3 = 63$

$3 \times \frac{5a + 155}{7} - 15 + 3 = 63$

$\frac{3(5a + 155)}{7} - 15 + 3 = 63$

$\frac{15a + 465}{7} - 15 + 3 = 63$

$\frac{15a + 465}{7} - 12 = 63$

$15a + 465 - 84 = 441$

$15a + 381 = 441$

$15a = 441 - 381$

$15a = 60$

$a = 4$