19.3.28 Linear Operators

Condition: is the display \ [\ left \ {\ begin {array} {l} y_ {1} = 0.1 x_ {1} -0.3 x_ {2} \\ y_ {2} = 0.4 x_ {1} +0.1 x_} \ end {array} \ Text {compressive in} \ mathbb {r} {1}^{2}, \ mathbb {r} {2}^{2}, \ mathbb {r} {\ infty}^{2}? \ Right. \]