1) y= 0.4x -5

13 = 0.4x -5

0.4x=18

х= 18/0.4 =45

2) =4^(2-3) + 1 - 2^(1-2) = 1/4 +1 -1/2= сводим к общему знаменателю = 1/4+ 4/4-2/4= 5/4-2/4 = 3/4