Given
we have
Squaring both sides, we have
And finally
Note that, when we square both sides, we have to assume that
because we're assuming that this fraction equals a square root, which is positive.
So, if that fraction is positive you'll actually have roots: choose
and you'll have
Which is a valid solution. If, instead, the fraction is negative, you'll have extraneous roots: choose
and you'll have
Squaring both sides (and here's the mistake!!) you'd have
which is not a solution for the equation, if we plug it in we have
Which is clearly false
Answer: it will take 7 seconds
Step-by-step explanation: 9 x 7 = 63
X + x + x + x - 20 is equivalent to 4x - 20 because you can add the like terms, or the x's.
It would be 60 because all you do is double the radius because it is only half of the circle