142k views
5 votes
Solve.

2x^2 + x - 1 = 2
A 1,2
B No real solutions
C 1,-3/2
D x = (-1 plus minus 3) over 2

User Dbeer
by
8.0k points

1 Answer

7 votes


2x^2+x-1=2\ \ \ |-2\\\\2x^2+x-3=0\\\\2x^2+3x-2x-3=0\\\\x(2x+3)-1(2x+3)=0\\\\(2x+3)(x-1)=0\iff 2x+3=0\ \vee\ x-1=0\\\\2x+3=0\ \ |-3\\2x=-3\ \ \ |:2\\x=-(3)/(2)\\\\x-1=0\ \ \ |+1\\x=1

Answer: C 1, -3/2

User DmitryArc
by
8.4k points