Graphing is a very useful tool to solve a system of equations but the only major disadvantage is that it is very time-consuming. So, we can solve the system of equations quickly by isolation one variable in one equation and then we get the answer by substituting the resulting expression for the variable in the other equation.
Step-by-step explanation :
Step 1:
Consider the system of equations:
5x + y =13
3x=15 - 3y
Step 2 :
y is the easiest variable to isolate in the first equation, because it has no coefficient:
y = 13 - 5x
Step 3 :
In the second equation, substituting for y :
3x = 15 - 3(13 - 5x)
Step 4 :
Solve the equation:
3x = 15 - 39 + 15x
3x = 15x - 24
-12x = - 24
x = 2
substituting this x-value into the "isolated equation" to find y:
y = 13 - 5x = 13 - 5(2) = 13 - 10 = 3
The solution to the system is (2, 3). This point is used to check for solutions in both equations.
Sample response:
Locate on the graph the point of intersection of the two linear equations. Determine which variable represents the values of the ordered pair by looking at the labels on the axes. Identify which coordinate goes with the variable needed to answer the question.
