I am trying to understand the underlying solution to this problem taken from Manhattan GMAT.
Find t :
t2(t-square)+2t+1=18
Since the equation cannot be factored easily, one can utilize a formula to derive t.
But MGmat solves the equation by:
(t+1)(t+1) = square root of 18...
culminating in a positive and negative t.
Question is : why square root the integer 18?
And why a positive and negative answer?
Quadratic Equation
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Positive and negative - because when you square a positive or negative number, the result will be positive. So the root of a positive number can be positive or a negative numbers
EX: -2 ^ 2 = 4 and 2^ 2 = 4 .. so the sq root 4 = +- 2
HTH
EX: -2 ^ 2 = 4 and 2^ 2 = 4 .. so the sq root 4 = +- 2
HTH
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Right.. Then, why square root of 18?
Is that a rule?
The equation is equal to 18..
You break down the equation into (t+1)(t+1)...
and all of the sudden, the equation is equal to square root of 18...
Is that a rule?
The equation is equal to 18..
You break down the equation into (t+1)(t+1)...
and all of the sudden, the equation is equal to square root of 18...
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(t +1)^2 = (t + 1)(t +1) = 18
Thus the square root of (t + 1)^2 = (t + 1) = square root of 18
Is this what you are asking about?
Thus the square root of (t + 1)^2 = (t + 1) = square root of 18
Is this what you are asking about?
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