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# i need help on the question

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(find the values of y)

ysquared =169

Jan 1, 2020
edited by Guest  Jan 1, 2020

#1
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Taking the square root of 169, you get y = 13.

But we also have to remember that y can be negative, giving us that y = -13.

So our answers are y = 13, and y = -13.

Jan 1, 2020
#2
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Thanks MathCuber

this is a good concept for you to work out quickly.

$$\sqrt{169}=+13\qquad \text{(never -13, this is by convention)}\\$$

However if

$$y^2=169$$

then it is you that must introduce the square root sign,

which means that both the negative and the positive are answer.

$$y^2=169\\ y=\pm\sqrt169\\ y=+13\;\;\;\;or\;\;\;\;y=-13$$

.
Jan 2, 2020