HELP HELP HELP 1) If y = −x − 7, then y = −x − 7? That is, can you replace y with −x − 7? Why?

2) Since you know that = −x − 7 and in the second equation with −x − 7, Can you replace the higher equation? Why?

3) Once you replace the of the second equation with, you have an equation with only one variable, like the one below. This is called substitution because what you do is substitute (replace)
with an expression of equal value. Solve this new equation to find use that result to find in any of the original equations.

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