Question

A.(3b-c)(3b+c)=9b^2-c^2 Решите пожалуйста B.36n^2-49=(6n+7)(7-6n) C.( x+4)(4-x)=16-x^2 D.y^4-25=(y^2-5)(y^2+5)

Answer 1

.......................

Answer 2

A. (3b-c)(3b+c) = 9b^2 - c^2

To solve this equation, we can use the difference of squares identity, which states that a^2 - b^2 = (a + b)(a - b).

In the given equation, we have (3b-c)(3b+c). We can rewrite this as (3b)^2 - (c)^2, which is in the form of the difference of squares.

Now, using the difference of squares identity, we can rewrite the equation as follows:

(3b-c)(3b+c) = (3b)^2 - (c)^2 = 9b^2 - c^2

Therefore, the given equation simplifies to 9b^2 - c^2.

B. 36n^2 - 49 = (6n+7)(7-6n)

To solve this equation, we can start by expanding the right side of the equation using the distributive property:

(6n+7)(7-6n) = 6n * 7 - 6n * 6n + 7 * 7 - 7 * 6n

Simplifying further, we have:

= 42n - 36n^2 + 49 - 42n

Combining like terms, we get:

= -36n^2 + 49

Therefore, the given equation simplifies to -36n^2 + 49.

C. (x+4)(4-x) = 16 - x^2

To solve this equation, we can start by expanding the left side of the equation using the distributive property:

(x+4)(4-x) = x * 4 - x * x + 4 * 4 - 4 * x

Simplifying further, we have:

= 4x - x^2 + 16 - 4x

Combining like terms, we get:

= -x^2 + 16

Therefore, the given equation simplifies to -x^2 + 16.

D. y^4 - 25 = (y^2-5)(y^2+5)

To solve this equation, we can start by expanding the right side of the equation using the distributive property:

(y^2-5)(y^2+5) = y^2 * y^2 + y^2 * 5 - 5 * y^2 - 5 * 5

Simplifying further, we have:

= y^4 + 5y^2 - 5y^2 - 25

Combining like terms, we get:

= y^4 - 25

Therefore, the given equation simplifies to y^4 - 25.