Question

Is my answer correct? :)

Solve. 2x2 - x = 15

Answer:
x = 3 and x = 1

Answer 1

that's incorrect

Answer 2

if you plug x = 1 into the equation, you get


2x^2-x = 15

2(1)^2-1 = 15

2(1)-1 = 15

2 - 1 = 15

1 = 15

which is FALSE


so x = 1 is NOT a solution

Answer 3

However, x = 3 is a solution because....

2x^2-x = 15

2(3)^2-3 = 15

2(9)-3 = 15

18 - 3 = 15

15 = 15

which is TRUE

so x = 3 is a solution

Answer 4

So you can use this idea to test possible solutions

Answer 5

x= 7/2
x = -1

?

Answer 6

2x^2-x = 15 only has 2 solutions and I just pointed one of those solutions out to you

Answer 7

x= -5/2

Answer 8

x=3

Answer 9

perfect, you got it