Answer:
52
Step-by-step explanation:
39, 40, 44, 49, 50, 54, 56, 61, 62, 68
39, 40, 44, 49, <u>50, 54,</u> 56, 61, 62, 68
=
= 52
Lets say you have 5 apples, but the you give away 3 of them.
To work how many you have left you take away.
5-3 = 2
Lets apply this with fractions now.
You have 9/7 yard, but then you give away 7/20 yard.
Now you take them away:
9/7 minus 7/20 = 131/140
Hope this helps :)
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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