Question

кто поможет дам 50 балов ​

Answer 1

$(3a - 2b) {}^{2} - (2a - b) {}^{2} = \\ (3a - 2b - 2a + b)(3a - 2b + 2a - b) = \\ (a - b)(5a - 3b) = \\ ( 1.35 - ( - 0.65))(5 \times 1.35 - 3 \times ( - 0.65)) = \\ (1.35 + 0.65)(6.75 + 1.95) = 2 \times 8.7 = 17.4$

$(2y - c) {}^{2} + (y + 2c) {}^{2} = \\ 4 {y}^{2} - 4cy + c {}^{2} + {y}^{2} + 4cy + 4 {c}^{2} = \\ 5y {}^{2} + 5 {c}^{2} = 5( {c}^{2} + y {}^{2} ) = \\ 5(1.2 {}^{2} + ( - 1.4) {}^{2} ) = 5(1.44 + 1.96) = \\ 5 \times 3.4 = 17$