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First of all, let the number be u.
The product of 7 and u means you should multiply 7 times u:
[tex]\pmb{7u}[/tex]
Now, subtract 4:
[tex]\pmb{7u-4}[/tex]
This expression equals 17:
[tex]\pmb{7u-4=17}[/tex]
[tex]\rule{200}{2}[/tex]
[Now, let's Find the Value of u]
First, add 4 to both sides:
[tex]\pmb{7u=21}[/tex]
Now, divide both sides by 7:
[tex]\pmb{u=3}[/tex]
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Hope everything is clear; if you need any clarification /explanation, kindly let me know, and I will comment and/or edit my answer :)
