1)=х^2+4х+4-49=х^2+4х-45
2)=х^2-20х+100-25у^2=-25у^2+х^2-20х+
+100
с)=64у^2+64у+16-16у^2+24у-9=48у^2+88у++7
д) =25с^2-36d^2-25c^2=-36d^2
e) =a^2-c^2-(a-2c)^2=a^2-c^2-a^2+4ac+4c^2=
=-5c^2+4ac
1)=х^2+4х+4-49=х^2+4х-45
2)=х^2-20х+100-25у^2=-25у^2+х^2-20х+
+100
с)=64у^2+64у+16-16у^2+24у-9=48у^2+88у++7
д) =25с^2-36d^2-25c^2=-36d^2
e) =a^2-c^2-(a-2c)^2=a^2-c^2-a^2+4ac+4c^2=
=-5c^2+4ac