Answer:
Step-by-step explanation:
3x - 7x -21 < -13
-4x < -13 + 21
-4x < 8
x > -2
[tex]3x - 7(x + 3) < -13 \\3x - 7x - 21 < -13 \\3x - 7x < -13 + 21 \\-4x < 8 \\x > -2[/tex]