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Solve each of the following for x:
a) 3x-5=100 b) 6(x-4)=12 c) 1/3x-10=20

1 Answer

5 votes

Answer:

a) x=105/3 = 35 b) x=6. c) x=90

Explanation:

A) 3x-5=100. To solve this we first add 5 to both sides and we get 3x=105. Then we divide both sides by 3 to find x. We then get x = 105/3 which simplifies to 35. To double check we can put 35 back into the equation and we get 3(35)-5=100 and we get 105-5=100. 100=100 Check

b)6 (x-4) = 12. First we need to divide both sides by 6. then after dividing both sides by 6 we are left with (x-4) = 2. Then we must add both sides by 4 to find x. We will then get x =6. To double check we can put 6 back into the equation and we get 6 (6-4) = 12 and we get 6(2) = 12. 12=12 check

c) 1/3x - 10 = 20. First we need to add 10 to both sides and we end up with 1/3x = 30. Then you can simplify this two ways. Either multiply both sides by 3 or divide both sides by 1/3, either way you will get the same answer. This will leave you with x = 90. To double check we can put 90 back into the equation and we get 1/3(90) - 10 = 20 and we get 30-10 = 20. 20=20 check

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