How do you factor #y= 2x^2 - 5x -3 #?
2 Answers
Dec 14, 2015
Use the quadratic formula to find:
#y = 2x^2-5x-3 = (2x+1)(x-3)#
Explanation:
This quadratic is of the form
#x = (-b+-sqrt(b^2-4ac))/(2a) = (5+-sqrt(5^2-(4xx2xx-3)))/(2xx2)#
#=(5+-sqrt(49))/4 = (5+-7)/4#
That is
Hence our quadratic has linear factors
#y = 2x^2-5x-3 = (2x+1)(x-3)#
Dec 14, 2015
Find a suitable split for the middle term, then factor by grouping to find:
#y = 2x^2-5x-3 =(2x+1)(x-3)#
Explanation:
Look for a pair of factors of
The pair
#y = 2x^2-5x-3#
#=2x^2-6x+x-3#
#=(2x^2-6x)+(x-3)#
#=2x(x-3)+1(x-3)#
#=(2x+1)(x-3)#