Mathematics Senior High about 3 yearsago

黒丸で囲んであるところの6zxって6xzじゃないんですか？

= (x²+2xy + y²) + (2x+2y)+1 = x² + 2xy + y² +2x+2y+1 (4) x-y=M とおくと (x-y-1)2 = (M-1)² = M² − 2M+1 =(x-y)^-2(x-y) +1 =(x²-2xy + y²) - (2x-2y)+1 2xy + y 2x+2y+1 (5) x+2y=M とおく (x+2y+3z) 2 =(M+32)² = M² +6Mz+9z² = (x+2y)² +6(x+2y)z+9z² =(x² + 4xy+4y²)+(6xz+12yz)+9z² =x²+4y² +9z²2 + 4xy+12yz +6zx) (6) 2x-y=M とくと (2x-y+3z)² =(M+32)² = M² +6M2+9z² = (2x - y)² +6(2x - y)z +9z² = (4x² - 4xy+ y²)+(12xz-6yz)+9z² = 4x² + y² +9z²-4xy-6yz+12zx 36 (1) x+y=Mとおくと (x+y+z)(x+y-z) =(M+2)(M-2) = M² — 2² (r+ y)²-2² = x² + 2xy + y² - 2²