Question

If 2x^2 + x = 6, then which of the following could be the value of 2x^2 – x?

Answer 1

\[\LARGE 2x^2+x-6=0 \quad use \quad x_{1/2}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}\]
since it's quadratic equation..

Answer 2

a=2 b=1 c=-6

Answer 3

\[\LARGE x_1=-2 \quad ,\quad x_2=\frac32\]

Answer 4

now substitute the values into the second equation... and find out what the solutions are... (If that's what is required...)

Answer 5

is it 4 ?

Answer 6

if you substitute x=3/2 you'll get 3 if you substitute x=-2 you'll get...10

Answer 7

\[\LARGE 2\cdot \left(\frac32\right)^2-\frac32\] continue... and do the same with the second one too.. ;)

Answer 8

ooo

Answer 9

I got it, great thanks! :D