12am*m*m-12an*n*n=12am³-12an³=12a(m³-n³)=12a(m-n)(m²+mn+n²)
<em>a</em>4<span> = </span><em>a</em>3<span> • </span><em>q</em><span> = (</span><em>a</em>1<span> • </span><em>q</em>2<span>) • </span><em>q</em><span> = </span><em>a</em>1<span> • </span><em>q</em>3
Y=(2/5)x-1 y=0,4x-1
<span>4x-10y=10, y=0,4x-1
графики этих уравнений совпадают</span>