Rezolvati prin metoda substitutiei urmatoarele sisteme:
a)
{2x-9y=-1
{-10x-7y+2

b) {3x-6y+3=0
{x+9y=-4

c)
{4a-b=9
{-6a+9b=-3

d)
{-2a-b=1
{-2a+4b=4

e)
{-10a-b=6
{7a-6b=-3
f)
{4a+8b=-6
{a-3b=6
g)
{10u+2v=5
{5u-7v=9
h)
{x-y=5
{-3x+8y=2