1)
3х+5у=16 ||×2
2х+3у=9 ||×(-3)
6х+10у=32
-6х-9у=-27
6х-6х+10у-9у=32-27
у=5
3х+5×5=16
3х+25=16
3х=16-25
3х=-9
х=-3
(-3;5)
==============
2)
9х-7у=95
4х+у=34 ||×7
9х-7у=95
28х+7у=238
9х+28х-7у+7у=238+95
37х=333
х=333÷37
х=9
у=34-4х=34-4×9=-2
(9;-2)
============
3)
2х+7у=44
2х-3у=-36 ||×(-1)
2х+7у=44
-2х+3у=36
2х-2х+3у+7у=44+36
10у=80
у=8
2х+7×8=44
2х+56=44
2х=44-56
2х=-12
х=-6
(-6;8)
==========
4)
х-8у=17
3х+4у=23 ||×2
х-8у=17
6х+8у=46
х+6х-8у+8у=17+46
7х=63
х=9
9-8у=17
-8у=17-9
-8у=8
у=-1
(9;-1)