Readiness Quiz
1)[ohm_question]144878[/ohm_question]
If you missed this problem, review the example below.
Evaluate [latex]x+7[/latex] when
 [latex]x=3[/latex]
 [latex]x=12[/latex]
Answer:
Solution:
1. To evaluate, substitute [latex]3[/latex] for [latex]x[/latex] in the expression, and then simplify.

[latex]x+7[/latex] 
Substitute. 
[latex]\color{red}{3}+7[/latex] 
Add. 
[latex]10[/latex] 
When [latex]x=3[/latex], the expression [latex]x+7[/latex] has a value of [latex]10[/latex].
2. To evaluate, substitute [latex]12[/latex] for [latex]x[/latex] in the expression, and then simplify.

[latex]x+7[/latex] 
Substitute. 
[latex]\color{red}{12}+7[/latex] 
Add. 
[latex]19[/latex] 
When [latex]x=12[/latex], the expression [latex]x+7[/latex] has a value of [latex]19[/latex].
Notice that we got different results for parts 1 and 2 even though we started with the same expression. This is because the values used for [latex]x[/latex] were different. When we evaluate an expression, the value varies depending on the value used for the variable.
2)[ohm_question]144884[/ohm_question]
If you missed this problem, review this example.
[latex]\text{Evaluate }3x+4y  6\text{ when }x=10\text{ and }y=2[/latex].
Answer: SolutionThis expression contains two variables, so we must make two substitutions.

[latex]3x+4y6[/latex] 
Substitute [latex]\color{red}{10}[/latex] for x and [latex]\color{blue}{2}[/latex] for y. 
[latex]3(\color{red}{10})+4(\color{blue}{2})6[/latex] 
Multiply. 
[latex]30+86[/latex] 
Add and subtract left to right. 
[latex]32[/latex] 
When [latex]x=10[/latex] and [latex]y=2[/latex], the expression [latex]3x+4y  6[/latex] has a value of [latex]32[/latex].
3)[ohm_question]142131[/ohm_question]
If you missed this problem, review the following video.
https://youtu.be/_hBoWoctfAo
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