1/0.25

0.25^2

1/0.0625

1+E//N

-2*0.75*2

A= (({{1, 0, 0, 0, 0}, {17, -34, 15, 0, 0}, {0, 18, -34, 14, 0}, {0, 0, 19, -34, 13}, {0, 0, 0, 0, 1}}));
c={1,-1,-2,-3,3.718};
LinearSolve[A,c]

DSolve[{y''[x]-2x*y'[x]-2y[x]== -4x,y[0]==1,y[1]== 1+E},y[x],x]

mrezha = {0,0.25,0.5,0.75,1};
yt[x_]:=(E^(x^2))+x

yt[mrezha]//N