iliailis69 1.а)=y²-8y+16; б)=49x²+14xa+a²; в)=(5с)²-1²; г)=(3а)²-(2b)².........2.(а-9)²-(81+2а)=а²-18а+81-81-2а=а²-20а=а(а-20)......3.а)=(х-7)(х+7); б)=(5х-у)²........4.(2-х)²-х(х+1,5)=4; 4-4х+х²-х²-1,5х-4=0; -5,5х=0; х=0.......5.а)=у⁴-4а²; б)=9х⁴+6х³+х²; в)=(4+2т+т²)(4-2т+т²)=16-8т+4т²+8т-4т²+2т³+4т²-2т³+т⁴=16+4т²+т⁴.....6.а)=(2ху-3а²)(2ху+3а²); б)=25а²-а²-6а-9=24а²-6а-9=3(8а²-2а-3); в)=(3т+п)(9т²-3тп+п²)