Answer:
x=4
Step-by-step explanation:
The question is
Find the value of x
we have
[tex]x-(4x-7)=5x-(x+21)[/tex]
solve for x
Eliminate parenthesis both sides
Remember that
[tex](-1)(-1)=+1\\(-1)(+1)=-1[/tex]
[tex]x-4x+7=5x-x-21[/tex]
Combine like terms
[tex]-3x+7=4x-21[/tex]
Group terms that contain the same variable
[tex]4x+3x=7+21\\7x=28\\x=4[/tex]