x？ =-343/5 12

x=-7/8

2. Root number (145? -24? )

= root number (145+24)*( 145-24)

= root number 169* root number 12 1

= 13* 1 1

= 143

3.a- 1=0，ab-2=0

a= 1 b=2

Evaluation) =1/2+1/6+...+1/2005 * 2006

= 1- 1/2+ 1/2- 1/3+ 1/3- 1/4+……+ 1/2005- 1/2006

= 1- 1/2006

=2005/2006

4. The square of10 minus the square of 6 equals 64, that is, the square of half the base length, that is, the root number 64 equals 8.

, so the base is twice that of 8, which is 16.

5. Because the sum of two numbers with opposite numbers is equal to 0, the sum of two numbers in five questions is equal to 0. The result is equal to the absolute value of X minus 12 plus the square of Y minus 13 plus the square of Z minus 5, so x= 12, y= 13 and z=5, and the three numbers are just complete.