Answer:
1
Step-by-step explanation:
[tex] {5x}^{4} + {7x}^{3} - 2 {x}^{2} - 3x + c \div (x + 1) \\ = (5 {x}^{3} + 2 {x}^{2} - 4x + 1)(x + 1) + c - 1 \\ \\ c - 1 = 0 \\ c = 1[/tex]
ok