F(x)=2.1x-7.5 x=3 f(3)=2.1*3-7.5 = -1.2 x=4 f(4)=2.1*4-7.5=0.9 x=0 f(0)=2.1*0-7.5=-7.5 f(x)=0.5x+2 f(3)=0.5*3+2=3.5 f(4)=0.5*4+2=4 f(0)=0.5*0+2=2 f(x)=8.6x-25.8 f(3)=8.6*3-25.8=0 f(4)=8.6*4-25.8=8.6 f(0)=8.6*0-25.8= - 25.8