Respuesta :
We must plugin values:
3(7)-4(0)=21, is CORRECT since 7•3 is 21 and -4•0 is 0
3(11)-4(3)=21 is CORRECT since 3•11=33 and -4•3=-12 so 33-12=21
3(-3)-4(3)=21 is INCORRECT since 3•-3 is -9 and -4•3 is -12, -9-12 is -21
3(-1)-4(-6)=21 is CORRECT since 3•-1 is -3 and -4•-6 is 24 and so 24-3=21
3(7)-4(0)=21, is CORRECT since 7•3 is 21 and -4•0 is 0
3(11)-4(3)=21 is CORRECT since 3•11=33 and -4•3=-12 so 33-12=21
3(-3)-4(3)=21 is INCORRECT since 3•-3 is -9 and -4•3 is -12, -9-12 is -21
3(-1)-4(-6)=21 is CORRECT since 3•-1 is -3 and -4•-6 is 24 and so 24-3=21