Simultaneous equations are two equations with two unknowns. And they can be solved by either elimination or substitution method.For this example, we will use the elimination method. First of all to make it easier you would simplify the equations if possible. In this case equation 1 is already simplified, whereas equation 2 can be simplified from 2x – y – 4 = 4 – x to 3x – y = 8 by collecting the like terms. In this equation, the unknows are y and x. As there is only 1 y in both equations, we will eliminate the y and calculate the value of x first. As equation 1 has ‘+1y’ and equation 2 has ‘-1y’. We will add the 2 equation together in order to eliminate y. Which will equal 5x = 15, and then to find the value of x divide by 5 on both sides which means x =3. Then substitute the value of x into the original equation to find the value of y. Thus 2(3) + y = 7. Which means 6 + y = 7 and therefore y = 1.