Question

Обчислити вирази: 1) (7m - 5n^2) - (2m - 8n^2); 2) 2m(2n - 3m) + 3m(5m - 3n)​

Answer 1

Ответ:

Упростить выражения .

Раскроем скобки и приведём подобные члены .

$\bf 1)\ \ (7m-5n^2)-(2m-8n^2)=(7m-2m)+(-5n^2+8n^2)=5m+3n^2\\\\\\2)\ \ 2m\, (2n-3m)+3m\, (5m-3n)=4\, m\, n-6m^2+15m^2-9\, m\, n=\\\\=(4\, m\, n-9\, m\, n)+(-6m^2+15m^2)=-5\, m\, n+9m^2$

Answer 2

1. (7m - 5n^2) - (2m - 8n^2):

To simplify this expression, we'll remove the parentheses and combine like terms:

7m - 5n^2 - 2m + 8n^2

Combining the terms with 'm' and 'n^2':

(7m - 2m) + (-5n^2 + 8n^2)

5m + 3n^2

Therefore, the simplified expression is 5m + 3n^2.

2. 2m(2n - 3m) + 3m(5m - 3n):

We'll apply the distributive property to expand the expression:

2m * 2n - 2m * 3m + 3m * 5m - 3m * 3n

Simplifying each term:

4mn - 6m^2 + 15m^2 - 9mn

Combining like terms:

4mn - 6m^2 + 15m^2 - 9mn

(-6m^2 + 15m^2) + (4mn - 9mn)

9m^2 - 5mn

Therefore, the simplified expression is 9m^2 - 5mn.