Question

(2b-3)(5b+7)+21 5a-(a+1 )(4a+1) (C+4 )(c-3)-(c×c+5c) x (2x-1)+(x+3)(x-5)

Answer 1

Прости я не поняла как третье записано

Answer 2

It seems like you have provided several mathematical expressions. Let's simplify each expression one by one:

1. (2b-3)(5b+7) + 21:

   To simplify this expression, you can use the distributive property (FOIL method):

   (2b * 5b) + (2b * 7) + (-3 * 5b) + (-3 * 7) + 21

   10b^2 + 14b - 15b - 21 + 21

   Now, combine like terms:

   10b^2 - b

2. 5a - (a + 1)(4a + 1):

   Apply the distributive property again:

   5a - (a * 4a) - (a * 1) - (1 * 4a) - (1 * 1)

   5a - 4a^2 - a - 4a - 1

   Now, combine like terms:

   5a - 4a^2 - 5a - 1

   -4a^2

3. (c + 4)(c - 3) - (c * c + 5c) * (2x - 1) + (x + 3)(x - 5):

   Start by simplifying each part of the expression separately:

   (c + 4)(c - 3) = c^2 - 3c + 4c - 12 = c^2 + c - 12

   (c * c + 5c) = c^2 + 5c

   Now, combine all the parts of the expression:

   (c^2 + c - 12) - (c^2 + 5c) * (2x - 1) + (x + 3)(x - 5)

   Now, distribute the -1 to the second term inside the parentheses:

   c^2 + c - 12 - (2x^2 - 5cx) + (x + 3)(x - 5)

   Now, distribute the (x + 3)(x - 5):

   c^2 + c - 12 - 2x^2 + 5cx + x^2 - 8x - 15

   Combine like terms:

   c^2 + x^2 + c - 8x + 5cx - 2x^2 - 12 - 15

   Simplify further:

   (c^2 + x^2 - 2x^2) + (c + 5cx) + (c - 12 - 15)

   -x^2 + 5cx + c - 27

So, the simplified expressions are:

1. 10b^2 - b
2. -4a^2
3. -x^2 + 5cx + c - 27