How do you factorise x^2 - 9.

1 answer:

4 0

X ^ 2 - 9

= x ^ 2 - 3 ^ 2

It turns into 3 ^ 2
Because 3 ^ 2 = 9

The final answer is
= ( x + 3 )( x - 3 )

remember the formula :

a^2 - b^2 =(a+b)(a-b)

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What four consecutive intergers have a sum of -34

Ivenika [448]

Answer:

-7, -8 , -9 and -10 are such four integers.

Step-by-step explanation:

Let the first integer = k

So, the next three consecutive integers are ( k+1), ((k + 1) + 1) and (((k + 1) + 1) +1)

or, k , (k +1), (k +2) and (k +3) are four consecutive integers.

Now, their sum is -34.

⇒k + (k +1) + (k +2) + (k +3) = -34

or, 4k + 6 = -34

or, 4k = - 34 - 6 = -40

⇒ k = -40/ 4 = -10

Hence, the first integer k = -10

The next integer = k + 1 = -10 + 1 = -9

Similarly next two integers are -8 and - 7.

So -7, -8 , -9 and -10 are such four integers.

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Step-by-step explanation:

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3 years ago

Solve it by Substitution

natka813 [3]

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To solve this problem, we first have to create a system of equations. After that, you set the equations equal to each other, and use that to simplify and find the value of one variable. Once that is found that answer can be plugged into one of the two original equations to find the other variable.