Solve -3x2 + 30x - 90 = 0.

1 answer:

6 0

$-3x^{2}+30x-90=0 \\ \\ x^{2}-10x+30=0 \\ \\ \Delta=(-10)^{2}-4*1*30=100-20=-20 \\ \\ \sqrt{\Delta}= \sqrt{-20}=i \sqrt{20} =2i \sqrt{5} \\ \\ x_{1}= \frac{10-2i \sqrt{5} }{2} = 5-i \sqrt{5} \\ \\ x_{2}= \frac{10+2i \sqrt{5} }{2} = 5+i \sqrt{5}$

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kkurt [141]

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22broccy-here you go g-<br> what is the sum of negative two squared plus one?

yaroslaw [1]

Answer:

The sum is equal to 5

Step-by-step explanation:

we know that

The algebraic expression of the phrase " the sum of negative two squared plus one" is equal to

$(-2)^{2}+1\\=4+1\\=5$