



 
Hi Laura, This problem is set up so that you can use the method of substitution directly. The first equation tell you an equivalent way to write x, it says that x is equivalent to 4 y + 5. Thus in the second equation, x + 2y = 7 you can replace x by this equivalent expression. Hence
can be rewritten
Another way to describe this is to say that I substituted 4 y + 5 for x. Now you have one equation in the variable that you can solve for y. Once you have a numerical value for y use x = 4 y + 5 to find a numerical value for x. At this point you can check that your answer is correct. Substitute the values of x and y you found into the second equation, x + 2y = 7, and see if it results in a true statement. If you need more helps write back,  


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