Factorize:
a)15x^2-51x+18.
=15x^2-45x -6x+18
=15x(x-3) - 6(x-3)
=(15x-6)(x-3)
b) x^3+13x^2+32x+20.
Notice that by changing the sign of odd powers, the coefficients add up to zero:
-1+13-32+20=0
So x+1 is a factor.
Divide by x+1 gives
x^2+12x+20
which factorizes readily to
(x+2)(x+10)
So the whole factorization is:
(x+1)(x+2)(x+10)
(c) x^2-5x/2-3/2.
=(1/2)(2x^2-5x-3)
=(1/2)[2x^2+x - 3(2x+1)]
=(1/2)[x(2x+1)-3(2x+1)]
=(1/2)(x-3)(2x+1)
(d) will be left as a practice for you.
the volume of a rectangular solid is given by expressions given below.in each case find the dimentions of the solid.
a)15x^2-51x+18.
b)x^3+13x^2+32x+20.
c)x^2-5x/2-3/2.
d)x^4+x^3-x-1
plz everyone help me out.till 2 o'clock...plz plz plz
1 answer
1 answer