Answer: x=3
Step-by-step explanation: Step 1: Simplify both sides of the equation.
21x−5=7+17x
21x+−5=7+17x
21x−5=17x+7
Step 2: Subtract 17x from both sides.
21x−5−17x=17x+7−17x
4x−5=7
Step 3: Add 5 to both sides.
4x−5+5=7+5
4x=12
Step 4: Divide both sides by 4.
= 
So Final Answer: <u>x=3</u>
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The answer is d because the perimeter of 6 by 6 would be 24 and that is the smallest perimeter.
1 hour = 60 min
0.5 hours = 60 * 0.5 = 30 min.