The product of two numbers is 8. Find the factor of 8: 1, 2, 4, 8.

X+Y=8 X+Y=4

X-Y= 1 (excluding) X-Y=2, and the solution is X=3.

Y= 1

2. Break 10ab into 8ab+2ab.

Then the original formula is = (a+b) 2+(ab+4) 2 = 0.

Get a+b=0 and ab+4=0, so a=2, b=-2 or a=-2, b=2.

a^2+b^2=8