Question 1120242
x<SUP>2</SUP>+4y<SUP>2</SUP>+16z<SUP>2</SUP>+4xy+16yz+8zx. First part, the equation factors to (x+2y+4z)<SUP>2</SUP> Next part, (x+2y+4z)<SUP>2</SUP>= (2+2(-1)+4(1))<SUP>2</SUP>=(2+(-2)+4)<SUP>2</SUP>=4<SUP>2</SUP>=16.