(2n+12) + (3n+18) = 180
⇒5n+30=180
⇒5n=150
⇒n=30
x=2n+12
=2(30)+12
=72°
I don't quite see any extraneous solutions, other than, the root is an even root, root of 2, and therefore, it will give you a ± solutions, if x = 6, the radicand becomes 0 then, and the roots for that will be ±0, keeping in mind 0 is neither per se.
now on the right-hand-side, 6-6 is just a flat positive 0, so the +0 root will match that, however the -0 will not, and thus can be seen as extraneous.
8x because everything else is addition or subtractionZ
Hello
the equation is y = ax+b
a the slop a = 0.5
y =0.5x+b
the line passes through (6,<span> -3) : -3 = 0.5(6)+b
b = -6
</span>the equation is y = 0.5x-6
13. 4/5
14.11/25
15.-1 7/20
16. 4/5
17. -1 5/10
18.4 9/20