Question

а)8x-3y,при x=3/4,y=-2/3
б)8x-3y,при x=-2/3,y=3/4 Помогите пожалуйста

Answer 1

$(8 \times \frac{3}{4} ) - (3 \times \frac{2}{3} ) = \frac{8 \times 3}{1 \times 4} - \frac{3 \times 2}{1 \times 3} = \frac{6}{1} - \frac{2}{1} = 6 - 2 = 4$
$(8 \times ( - \frac{2}{3} )) - (3 \times \frac{3}{4} ) = ( - \frac{8 \times 2}{1 \times 3} ) - ( \frac{3 \times 3}{1 \times 4} ) = - \frac{16}{3} - \frac{9}{4} = - 5 \frac{1}{3} - 2 \frac{1}{4} = - 7 \frac{4 + 3}{12} = - 7 \frac{7}{12}$