Question

Упростите выражение
5/7(2.8c-4 1/5d)-2.4(5/6c-1.5d)
/ Дробь
4 целых 1-на 5-я

Answer 1

⁵/₇(2,8c-4¹/₅d)-2,4(⁵/₆c-1,5d) = 0,6d
1) ⁵/₇(2,8c-4¹/₅d) = ⁵/₇ײ⁸/₁₀c - ⁵/₇ײ¹/₅d =⁵ˣ²⁸/₇ₓ₁₀c - ²¹ˣ⁵/₅ₓ₇d = ⁴/₂с - 3d = 2c - 3d
2) 2,4(⁵/₆c-1,5d) =2,4×⁵/₆c - 2,4×1,5d =²⁴/₁₀×⁵/₆c - 3,6d =²⁴ˣ⁵/₁₀ₓ₆c-3,6d = ⁴/₂c-3,6d = 2c-3,6d
3) (2c - 3d) - (2c-3,6d) = 2c - 3d - 2c + 3,6d = 0,6d