A linear equation can be written in different ways. An equation containing two variables x and y is said to form a linear equation in two variables. The highest degree of both the variables x and y in the equation is 1.

Simultaneous quadratics contains two equations, one linear equation and one quadratic equation. Any equation whose highest degree is 2 is called a quadratic equation.

The solutions of the quadratic equation are called zero or the root of the equation. For quadratic equation, the equation has two roots or zeros.

A quadratic equation is a polynomial equation of degree of order 2. ax^2 + bx + c is the general form of a quadratic polynomial. If we equate this polynomial to zero, we get a quadratic equation. The general form of a quadratic equation is ax^2 + bx + c = 0.

A simultaneous equation is where two algebraic expressions (typically in terms of x and y) intersect with each other. When you solve for a simultaneous equation, you are solving for both x and y. And they are co-ordinates.