Hey!
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Steps To Solve:
20 + 4x = 28
~Subtract 20 to both sides
20 + 4x - 20 = 28 - 20
~Simplify
4x = 8
~Divide 4 to both sides
4x/4 = 8/4
~Simplify
x = 2
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Hence, the answer is [tex]\Large\boxed{\mathsf{x~=~2}}[/tex]
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Hope This Helped! Good Luck!