1.
[tex](-2,3) \\
x=-2 \\
y=3 \\ \Downarrow \\
-2+3 \times 3<9 \\
-2+9<9 \\
7<9 \\
true \\ \\
(-1,4) \\ x=-1 \\ y=4 \\ \Downarrow \\
-1+3 \times 4<9 \\
-1+12 < 9 \\
11<9 \\
not \ true \\ \\
(1,3) \\ x=1 \\ y=3 \\ \Downarrow \\
1+3 \times 3<9 \\
1+9<9 \\
10<9 \\
not \ true \\ \\
(5,1) \\
x=5 \\ y=1 \\ \Downarrow \\
5+3 \times 1<9 \\
5+3 <9 \\
8<9 \\
true[/tex]
The ordered pairs (-2,3) and (5,1) make the inequality true.
2.
[tex]15y-3(4y+10)=15y-3 \times 4y-3 \times 10= 15y-12y-30= \\
=3y-30[/tex]
The simplified form of the expression is 3y-30.