Question

Give the values of a, b, and c from the general form of the equation (2x + 1)(x - 2) = 0.

a) a = 2, b = -3, c = -2
b) a = 2, b = 5, c = -2
c) a = 3, b = 1, c = -1

Answer 1

i guess they want you to multiply
\[(2x+1)(x-2)\] do you know how to do that?

Answer 2

you have to do four multiplications, which some idiot math teachers like to call "foil" but in fact is the distributive law
\[(2x+1)(x-2)=2x\times x-2\times 2x+1\times x+1\times (-2)\] which cleans up to
\[2x^2-4x+x-2\] combining like terms gives
\[x^2-3x-1\]

Answer 3

another typo
it must be my bed time
last line should be
\[\huge 2x^2-3x-2\]