По формуле a²-b<span>²=(a-b)(a+b)
</span>1) <span>9х²-1=(3x-1)(3x+1)
</span>2) <span>1-16а²=(1-4a)(1+4a)
</span>3) <span>81-49b²=(9-7b)(9+7b)
</span>4) <span>100p²-64q²=(10p-8q)(10p+8q)
</span>5)-c²+16d²=-(c²-16d²)=-(c-4d)(c+4d)
6)<span>144z²-0.25t²=(12z-0,5t)(12z+0,5t)
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