それぞれの問題ごとに、分配法則や展開、有理化などの計算テクニックを用いて計算を進めます。
(1) (2+1)(3+2)=6+22+3+2 (2) (32−1)(2−3)=3⋅2−92−2+3=6−102+3=9−102 (3) (2−3)(2+5)=2+52−32−15=22−13 (4) (23+6)(23−7)=4⋅3−143+123−42=12−23−42=−30−23 (5) (6−23)(6+3)=6+18−218−2⋅3=6+32−62−6=−32 (6) (43−26)(43+6)=16⋅3+418−818−2⋅6=48+122−242−12=36−122 (7) (2+1)2=(2)2+22+1=2+22+1=3+22 (8) (23+5)2=(23)2+2⋅235+(5)2=4⋅3+415+5=12+415+5=17+415 (9) (3+6)2=(3)2+218+(6)2=3+2⋅32+6=9+62 (10) (3−4)2=(3)2−2⋅43+42=3−83+16=19−83 (11) (5−2)2=(5)2−210+(2)2=5−210+2=7−210 (12) (23−2)2=(23)2−2⋅232+(2)2=4⋅3−46+2=12−46+2=14−46 (13) (4+23)(4−23)=42−(23)2=16−4⋅3=16−12=4 (14) (23+22)(23−22)=(23)2−(22)2=4⋅3−4⋅2=12−8=4 (15) (3+2)2−48=3+43+4−43=7 (16) (5+3)(5−3)+1248=(5−3)+1248=2+4=2+2=4 (17) (33+1)(1−3)−(1−3)2=33−9+1−3−(1−23+3)=23−8−(4−23)=23−8−4+23=43−12 (18) (4−2)2−(5−23)(5+23)=(16−82+2)−(5−4⋅3)=18−82−(5−12)=18−82−(−7)=18−82+7=25−82