[tex]A. \\ (4,0) \\
a=4 \\ b=0 \\ \Downarrow \\ 7 \times 4-5 \times 0 \stackrel{?}{=} 28 \\ 28-0 \stackrel{?}{=} 28 \\ 28\stackrel{?}{=} 28 \\ 28=28 \\
true[/tex]
[tex]B. \\ (0,4) \\
a=0 \\ b=4 \\ \Downarrow \\
7 \times 0 - 5 \times 4 \stackrel{?}{=} 28 \\
0-20 \stackrel{?}{=} 28 \\
-20 \stackrel{?}{=} 28 \\
-20 \not= 28 \\
not \ true[/tex]
[tex]C. \\
(-2,-3) \\
a=-2 \\ b=-3 \\ \Downarrow \\
7 \times (-2) - 5 \times (-3) \stackrel{?}{=} 28 \\
-14+15 \stackrel{?}{=} 28 \\
1 \stackrel{?}{=} 28 \\
1 \not= 28 \\
not \ true[/tex]
[tex]D. \\
(-3,-2) \\
a=-3 \\ b=-2 \\ \Downarrow \\
7 \times (-3) -5 \times (-2) \stackrel{?}{=} 28 \\
-21 +10 \stackrel{?}{=} 28 \\
-11 \stackrel{?}{=} 28 \\
-11 \not= 28 \\ not \ true[/tex]
The answer is A.
