PROGRAM Tridiagonal !The number of variable or number of equations is n. !The coefficient matrix=a(ij), i, j=1,2,3,...,n. !The lower triangular matrix=l(ij), i, j=1,2,3,...,n. !The upper matrix=u(ij), i, j=1,2,3,...,n. !b(i), i=1,2,3,...,n, the constants of the of the equations. !z(i), i=1,2,3,...,n. !x(i), i=1,2,3,...,n. integer::n,i,j,k,m real:: a(5),b(5),c(5),p(5),q(5),r(5),x(5),z(5),d(5) open(9,file="input.dat") open(10,file="output10") read(9,*)n read(9,*)(a(j),j=1,n) read(9,*)(b(j),j=1,n-1) read(9,*)(c(j),j=2,n) read(9,*)(d(j),j=1,n) write(10,*)"a="," ",(a(j),j=1,n) write(10,*)" " write(10,*)"b="," ",(b(j),j=1,n-1) write(10,*)" " write(10,*)"c="," ",(c(j),j=2,n) write(10,*)" " write(10,*)"d="," ",(d(j),j=1,n) r(1)=a(1) do i=2,n q(i)=c(i) p(i-1)=b(i-1)/r(i-1) r(i)=a(i)-p(i-1)*q(i) write(10,*)"i=",i,"p,q,r=",p(i),q(i),r(i) enddo writ...