Question 1027817
you want to get the quadratic equation into standard form first.


that form is ax^2 + bx + c = 0


a is the coefficient of the x^2 term.
b is the coefficient of the x term.
c is the constant term.


your equation is:


7x(x+2)+5=3x(x+1)       


simplify by performing the operations indicated to get:


7x^2 + 14x = 3x^2 + 3x


not subtract all the terms on the right hand side from both sides of the equation to get:


7x^2 + 14x - 3x^2 - 3x = 0


now combine like terms to get:


4x^2 + 11x = 0


it is now in standard form of ax^2 + bx + c = 0


a = 4
b = 11
c = 0


now you can use the quadratic formula of x = (-b plus or minus sqrt(b^2-4ac)/(2a).


that will get you x = 0 or x = -22/8 which can be simplified to x = -11/4.


the graph of the resulting equation confirms that, as shown below:


<img src = "http://theo.x10hosting.com/2016/040301.jpg" alt="$$$" </>


the decimal equivalent of -11/4 is -2.75, as shown on the graph.