Step-by-step explanation:
We just subsitue 3 for x and -4 for y, so we get
[tex]3(3) - 5( - 4) = 9 + 20 = 29[/tex]
So
[tex]a = 29[/tex]
[tex]7(3) + ( - 4) = b[/tex]
[tex]21 - 4 = 17[/tex]
[tex]b = 17[/tex]
