Answer:
a) f(1/2)= - 4, b) f(x)=0 when x=-0.5, x=0.633,x= - 1.383
Explanation:
f(x):(2x+1)=8x²+6x-7
f(x)=(2x+1)*(8x²+6x-7)
a) f(1/2)= (2*(1/2)+1)*(8*(1/2)²+6*(1/2)-7)=(1+1)(2+3-7)=2*-2= - 4
f(1/2)= - 4
b) f(x)=0
(2x+1)*(8x²+6x-7)=0
2x+1=0, x= - 1/2
8x²+6x-7=0
x=(-b+/-√(b^2-4ac))/2a
x=(-6+/-√(6²-4*8*(-7)))/2*8=(-6+/-√(260))/16
x=0.633 and x=-1.383