f(x) = 2x3 – 5x2 + ax + 18 where a is a constant. Given that (x – 3) is a factor of f(x), (a) show that a = – 9 (2) (b) factorise f(x) completely. (4) Given that g(y) = 2(33y ) – 5(32y ) – 9(3y ) + 18 (c) find the values of y that satisfy g(y) = 0, givi

a) 54-45+3a+18=0 3a+27=0 3a=-27 and thus a=-9b) 2x^3 – 5x^2 -9x + 18 = (x-3) (2x^2 +bx-6)to find b ; collect the x^2 terms so bx^2-6x^2=-5x^2 and thus b=1c) when comparing f(y) and f(x) we see that x=3^2yf(x)=(x-3) , (2x-3) , (x+2)so x = 3 x=3/2 and x=-2when x=3 , y=1when x=-2 , no solution and when x=2/3 , take logs woth base of 3 and you get y=0.3690