1 40,8-(-2,6) y-7条: (-9)

Ответ: 43,4; y = 54

Решение:

1. 40,8 - (-2,6) = 40,8 + 2,6 = 43,4
2. y - 7\(\frac{6}{7}\) = -9
3. y = -9 + 7\(\frac{6}{7}\)
4. y = -\(\frac{63}{7}\) + \(\frac{55}{7}\) = -\(\frac{8}{7}\) = -1\(\frac{1}{7}\)

Ответ: 43,4; y = -1\(\frac{1}{7}\)