Math Question

[tigerton]

<p>I am practicing in the blue book, I came across this question and got it right; but I am wondering something.</p>

<p>Test 2, Section 2
19) The square of x is equal to 4 times the square of y. If x is 1 more than twice y, what is the value of x?
So to solve it first I wrote the equations.
x^2=4y^2 and x=2y +1</p>

<p>Then I substituted and got (2y + 1)^2=4y^2.</p>

<p>Then I simply just squared and solved for y, then used y to find x.</p>

<p>My question is, why doesn't it work when you square root both sides?</p>

[shmluza]

<p>Yes it works if you square root both sides, just remember when you sqrt(4y^2), you get both +2y and -2y. The -2y will lead you to the correct answer.</p>