1. It is known that the square of (x+3) +|y+ 1|+z is 0.

If the sum of non-negative numbers is zero, then each non-negative number is zero.

x+3=0，y+ 1=0，z=0

x=-3，y=- 1，z=0

So the square of x+the square of y+the square of z =9+ 1+0= 10.

2.a+2b = 5x's cube of X +2 *(x's square-1 1x+6)= 5x's cube +2x's square -22x+ 12 = 3x's cube -22x+65438.

3.(4a square -3a)-( 1-4a square) =4a square -3a- 1+4a square = a- 1 =-3.

4. Set the unit price of schoolbag X.

4x-8+x=452

5x=452+8

5x=460

x=92

452-92=360

The unit price of schoolbag is 92 yuan, and the Walkman is 360 yuan.