\[\boxed{\text{1001.}\text{\ }еуроки - ответы\ на\ пятёрку}\]
\[\textbf{а)}\ (3a - 2b)^{2} - (2a - b)^{2} =\]
\[= (3a - 2b - 2a + b)\]
\[(3a - 2b + 2a - b) =\]
\[= (a - b)(5a - 3b)\]
\[если\ a = 1,35;\ \ \ \ b = - 0,65:\ \ \ \]
\[(1,35 + 0,65)\]
\[\left( 5 \cdot 1,35 - 3 \cdot ( - 0,65) \right) =\]
\[= 2 \cdot (6,75 + 1,95) =\]
\[= 2 \cdot 8,7 = 17,4\]
\[\textbf{б)}\ (2y - c)^{2} + (y + 2c)^{2} =\]
\[\text{=}4y^{2} - 4yc + c^{2} + y^{2} +\]
\[+ 4yc + 4c^{2} =\]
\[= 5y^{2} + 5c^{2} = 5 \cdot \left( y^{2} + c^{2} \right)\]
\[если\ \ y = - 1,4;\ \ \ \ c = 1,2:\]
\[5 \cdot \left( ( - 1,4)^{2} + (1,2)^{2} \right) =\]
\[= 5 \cdot (1,96 + 1,44) =\]
\[= 5 \cdot 3,4 = 17\]