16а3-а7=а3(16-а4)=а3(4-а2)(4+а2)=а3(2-а)(2+а)(4+а2)
(х-3)2+5=х2-4
х2-6х+9+5-х2+4=0
-6х+18=0
-6(х-3)=0
16а3-а7=а3(16-а4)=а3(4-а2)(4+а2)=а3(2-а)(2+а)(4+а2)
(х-3)2+5=х2-4
х2-6х+9+5-х2+4=0
-6х+18=0
-6(х-3)=0