[tex]-7(3x-7)+21x\geq50\qquad|\text{use distributive property}\\\\(-7)(3x)+(-7)(-7)+21x\geq50\\\\-21x+49+21x\geq50\\\\(-21x+21x)+49\geq50\\\\49\geq50\ FALSE\\\\Answer:\ \text{a - no solution}[/tex]