1) (3а²+в)(9а⁴-3а²в+в²)-26а⁶=3а³+в³-26а⁶
2) (а+в+2)²-2(а+в+2)(1-2в)+(1-2в)²=(а+в=2)-2(1-2в)=а+в+2-2-4в=-3в+а
3) (2х-1)(4х²+2х+1)-8х(х²-1)=3х+4
2х²-1²-8х³+8х=3х+4
2х²-8х³+8х-3х=4+1²
-11х=5
х=-5/11
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5) 15⁴-186²+173²-134²=50625-34596+29929-17956=28002÷39=718