Question

Выполнить действие: 1) (b-9)^2 2) (7+6a)^2 3) (4c-y)(4c+y)

Answer 1

1) = b²-18b+81
2) = 49+84a+36a²
3) = 16c²-y² 

Answer 2

I can help you with some math problems. Here are the steps to perform the actions you requested:

1) $(b-9)^2$ To square a binomial, we use the formula $(a-b)^2=a^2-2ab+b^2$. In this case, $a=b$ and $b=9$, so we get: \begin{align*} (b-9)^2&=b^2-2(b)(9)+9^2\\ &=b^2-18b+81 \end{align*}

2) $(7+6a)^2$ To square a binomial, we use the formula $(a+b)^2=a^2+2ab+b^2$. In this case, $a=7$ and $b=6a$, so we get: \begin{align*} (7+6a)^2&=7^2+2(7)(6a)+(6a)^2\\ &=49+84a+36a^2 \end{align*}

3) $(4c-y)(4c+y)$ To multiply two binomials, we use the distributive property. We multiply each term in the first binomial by each term in the second binomial, and then add the results. In this case, we get: \begin{align*} (4c-y)(4c+y)&=(4c)(4c)+(4c)(y)+(-y)(4c)+(-y)(y)\\ &=16c^2+4cy-4cy-y^2\\ &=16c^2-y^2 \end{align*}

You can also use the formula $(a-b)(a+b)=a^2-b^2$ to get the same result.

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