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Factoriser 30x²-11x-6

User Runway
by
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2 Answers

7 votes

Answer:

x=2/3 or x= -3/10

Explanation:

30x²-11x-6=0

ax²+bx+c=0

30x²+9x-20x-6=0

3x(10x+3)-2(10x+3)=0

(3x-2)(10x+3)=0

3x-2=0 or 10x+3=0

3x=2 or 10x= -3

x=2/3 or x= -3/10

User Rrcal
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7.3k points
3 votes
We can use the general factoring method of finding two numbers that multiply to give -6 and add to give -11. In this case, the two numbers are -2 and -3.

Starting with the first term, 30x²:

Multiply the coefficient (30) by the two numbers we found (-2 and -3) to give 60 and -90.
Write the expression as (6x - 2)(5x + 3) and distribute the first term, 30x², as follows:
30x² = (6x - 2)(5x) + (6x - 2)(3)

Next, the middle term, -11x:

Distribute -11x as follows:
-11x = (6x)(-3) + (-2)(5x)

Finally, the last term, -6:

Distribute -6 as follows:
-6 = (6x - 2)(-3) + (-2)(3)

Putting all of this together, we have:

30x² - 11x - 6 = (6x - 2)(5x) + (6x - 2)(3) - (6x)(-3) - (-2)(5x) - (6x - 2)(-3) - (-2)(3)

Combining like terms:

30x² - 11x - 6 = (6x - 2)(5x + 3)

So, 30x² - 11x - 6 can be factored as (6x - 2)(5x + 3).
User Pavel Krymets
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7.6k points