a) <span>(2x-y)(y+2x)+x(4-3x)</span>
<span><span>2x^2-y^2+4x-12x</span></span>
<span><span>2x^2-y^2-8x</span></span>
<span><span><span>б) (a+b)(a-b)-(a-b)^2</span></span></span>
<span><span><span>a^2-b^2-(a^2-2ab+b^2)</span></span></span>
<span><span><span>a^2-b^2-a^2+2ab-b^2</span></span></span>
<span><span><span>2ab-2b^2</span></span></span>
<span><span><span>2b(a-b)</span></span></span>
<span><span><span><span>в) (2a+1)^2+(1-2a)(1+2a)</span></span></span></span>
<span><span><span><span>4a^2+8a+1+1-4a^2</span></span></span></span>
<span><span><span><span>8a+2</span></span></span></span>
<span><span><span><span>2(4a+1)</span></span></span></span>