Factor the given trinomial.

Question

5x^2--18x+9. Show all work 

Answer 1

To factor 5x²-18x+9, 

 

(5x   )( x    ) <--step 1, first terms are 5x and x.

 

For the last terms, find multiples of 9 that when using F.O.I.L. with 5x and x equals -18x in the middle, both signs must be negative.

 

 

3*3 <---Use this and check. (i.e. -3 and -3)

9*1

 

Check: 

(5x-3)(x-3) 

Multiplied out using FOIL: 5x²-15x-3x+9

Combine like terms: 5X^2-18x+9.

 

The answer is (5x-3)(x-3).