Question 141122
5x^2+3x-2=0
.
factoring:
5*-2=-10
What 2 factors of -10 add up 3? Ans: 5 and -2.
5x^2+5x-2x-2=0
5x(x+1)-2(x+1)=0 Factoring by grouping.
(5x-2)(x+1)=0
5x=2 x=2/5
x=-1
.
Completing the square:
5x^2+3x-2=0
x^2+ 3x/5 - 2/5 = 0
x^2+.6x-.4=0
x^2+.6x =.4
x^2+.6x+.09=.4+.09 Complete the square by dividing the middle term by 2 and squaring the result.
(x+.3)^2=.49
x+.3=+-.7
x=-.3+-.7
x=.4, x=-1
.
Ed
.
*[invoke solve_quadratic_equation 5, 3, -2]