squareroots

[shy cape]

why ping me

[gritty harbor]

so question 10 how did they remove the root

?

they squared it

like they did (y^2)^2

(-x)^2 is always positive

in number 10 they still end up with the correct answer because at the end they have the plus/minus

for both solutions +ve and -ve

It's the same thing, you could have written it as (x-3)^2 = 4y^4, then solve it similarly to 10

so (x-3) = 4y^4

=> x = 4y^4 + 3
x = +/- sqrt(4y^4 + 3)

i think actually the way you've done it leads to a nicer answer but they're equivalent

generally just shoving in a plus/minus gives less working out but you might have a less nice answer

if that makes sense

you'll find that as you're doing different maths where the focus isn't the actual solution to equations (which obviously is really important to understand that's why you're learning it) then the extra work doing that doesn't really help at all

and as questions stop giving nice solutions

either way you'll get the right answer though so just do what your confortable with, and that goes for most maths