Question

помагите пажалуйста :
x + 3x + 5 = 17
3,5x + 2,2x = 4,56

Answer 1

$x + 3x + 5 = 17 \\ 4x + 5 = 17 \\ 4x = 17 - 5 \\ 4x = 12 \\ x = 3 \\ \\ 3.5x + 2.2x = 4.56 \\ 5.7x = 4.56 \\ x = 0.8$