21x + y = - 15.1 \\ y = 0.9 - x \\
21 x + 0.9 - x = - 15.1 \\ 20 x = - 16 \\ x = - \frac{16}{20} \\ x = - 0.8
y = 0.9 - ( - 0.8) = 1.7 \\
ответ: x= -0.8 y= 1.7
21x + y = - 15.1 \\ y = 0.9 - x \\
21 x + 0.9 - x = - 15.1 \\ 20 x = - 16 \\ x = - \frac{16}{20} \\ x = - 0.8
y = 0.9 - ( - 0.8) = 1.7 \\
ответ: x= -0.8 y= 1.7