Question

初二二次根式计算题：看图

Answer 1

原式=5/4*√[(a+b)(a-b)/6x²*x^4/3(a+b)*b/(a-b)]
=5/4*√[x²b/18]

=5/4*|x|/6*√(2b)
=5|x|√(2b)/24

Answer 2

△=[-(k+2)]²-8k
=k²+4k+4-8k
=k²-4k+4
=(k+2)²≥0
选B
即|x-2|>=0
-|x-2|<=0
3-|x-2|<=3
所以最大值是3