As the equation is of the form +,+,-,find mentally 2 numbers whose sum is +7 and product is 12*(-10)=-120.One number will be positive and the other negative such that +ve no. > -ve no. (As their sum is a postive number)Such numbers are +15 and -8.
Therefore,the equation can be written as:
factorizing the (1st and 2nd ) and (3rd and 4th) terms together,we get
Either 3x-2=0 or 4x+5=0
Either 3x=2 or 4x=-5
Either x=2/3 or x=-5/4
Ans:The 2 roots of the equation are: x=2/3 or -5/4.