Countdown to Exams - Day 66 - Simultaneous equations
In today's blog post we cast our eye on Simultaneous equations. A simultaneous equation is where we have two equations containing different unknowns (normally x's and y's) and our job is to find the value of both of these letters. There are two ways to solve simultaneous equations; the first method is the elimination method. In this method the aim is to get one of your variables to have matching coefficients, we achieve this by multiplying one or both of the equations. When the are the same we simply add or subtract the equations to eliminate a variable. Solve the resultant equation to find the value of one variable. Remember to substitute this value into an equation to find the value of the second variable to get full marks.
The second method is the substitution method. In this method, the aim is to rearrange one of the equations so that a variable is equal to something. This something is then substituted into the other equation (this leaves one equation with one variable in it). Solve the resultant equation to find the value of one variable. Remember to substitute this value into an equation to find the value of the second variable to get full marks.
If there are quadratics present, be sure to use the substitution method.
In the video below, Matt goes through the process required to solve simultaneous equations using both methods.
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