Let's try to solve this quadratic equation
Without using calculator, solve the following quadratic equation and put the solutions as their sum.
x 2 − 1 9 4 5 x + 7 7 6 4 = 0
Bonus : Did you notice any special relationship between them?
The answer is 1945.
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2 solutions
Thanks you, that looks nicer
Null factor law
x 2 − 1 9 4 5 x + 7 7 6 4 = 0 x 2 − 1 9 4 1 x − 4 x + 7 7 6 4 = 0 x ( x − 1 9 4 1 ) − 4 ( x − 1 9 4 1 ) = 0 ( x − 4 ) ( x − 1 9 4 1 ) = 0 x = 4 o r x = 1 9 4 1
Therefore, the answer would be 4 + 1 9 4 1 = 1 9 4 5
I believe there is a shorter way do this...
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Do you mean to use Δ = b 2 − 4 a c ?
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In my mind more like...
( x 1 + x 2 ) = a − b
My math teacher ever told me about that, So since you only need to find the sum of the solutions... I'm not a good speaker tho :/
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@Tawaf Nasution – Oh, that's Vieta formula.
Just in case you wonder, here is it .
There's no need to factor the quadratic. Sum of roots can be easily obtained by vieta's formula .
Applying the formula, the sum comes as
− 1 − 1 9 4 5 = 1 9 4 5