Question

x2 = 3x + 5 solve

Answer 1

\[x ^{2} = 3x+5\]

To solve this, subtract both 3x and 5 so that everything is on one side if the = sign and there is a 0 on the other:

\[x ^{2}-3x-5=0\]
Now you have the equation in standard form: \[ax ^{2}+bx+c=y\]

Look at the equation you have now and see if it is factorable. It is not because there are no two numbers that can multiply to -5 and add to -3. You must use the quadratic formula to factor it out:

\[x = (-b \pm \sqrt{b ^{2}-4ac})\div2a\]

(Plug in and solve)