Question

Упрастите выражение 7 класс

Answer 1

1.

$(10a - 6b + 5c - 4d) - (9a - 2b - 4c + 2d) = 10a - 6b + 5c - 4d - 9a + 2b + 4c - 2d = (10a - 9a) + ( - 6b + 2b) + (5c + 4c) + ( - 4d - 2d) = 1a + ( - 4b) + 9c + ( - 6d) = a - 4b + 9c - 6d$

2.

$(5 {a}^{2} - ax + {x}^{2} ) + (3 {a}^{2} + 2ax - 3 {x}^{2} ) - (4ax + 2 {x}^{2} + {a}^{2} ) = 5 {a}^{2} - ax + {x}^{2} + 3 {a}^{2} + 2ax - 3 {x}^{2} - 4ax - 2 {x}^{2} - {a}^{2} = (5 {a}^{2} + 3 {a}^{2} - {a}^{2} ) + ( - ax + 2ax - 4ax) + ( {x}^{2} - 3 {x}^{2} - 2 {x}^{2} ) = 7 {a}^{2} + ( - 3ax) + ( - 4 {x}^{2} ) = 7 {a}^{2} - 3ax - 4 {x}^{2}$

3.

$(2 {m}^{4} + 5 {m}^{3} n - 3 {m}^{2} {n}^{2} - m{n}^{3} ) + (3 {m}^{4} - 8 {m}^{3} {n}^{2} - 6m {n}^{3} ) = 2 {m}^{4} + 5 {m}^{3} n - 3 {m}^{2} {n}^{2} - m {n}^{3} + 3 {m}^{4} - 8 {m}^{3} {n}^{2} - 6m {n}^{3} = (2 {m}^{4} + 3 {m}^{4} ) + (5 {m}^{3} n) + ( - 3 {m}^{2} {n}^{2} ) + ( - m {n}^{3} - 6m {n}^{3} ) + ( - 8 {m}^{3} {n}^{2} ) = 5 {m}^{4} + 5 {m}^{3} n - 3 {m}^{2} {n}^{2} - 7m {n}^{3} - 8 {m}^{3} {n}^{2}$