The new equation after the expression equivalent to x from the first equation is substituted into the second equation is: 
Step-by-step explanation:
We will solve the initial steps for substitution method for finding the correct answer
Given equations are:

From equation one

Putting x = -4y-9 in equation 2

Hence,
The new equation after the expression equivalent to x from the first equation is substituted into the second equation is: 
Keywords: Linear equations, variables
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Mark has to ride 50 kilometers. He already rode 18.23 and 13.94.
18.23km+13.94km=32.17km
50km-32.17km=17.83km
Mark will have to ride 17.83km more. The correct answer is B.
I’m almost 100% sure that it’s the option directly above the one that you chose
There is no image or problem so I can't really help you sorry