Question 505262: The product of 4 and a number is the same as 30 less twice that same number. Find the number
Thank you for your help
Answer by melshlovo(4)   (Show Source):
You can put this solution on YOUR website! The answer is -15. Let x be the unknown number, since the problem stated that the number is multiplied by 4, the first quantity must be 4x. The phrase 'same as' would give you a clue that it is an equation, which means the first quantity (4x) is equal to the second quantity which is stated as '30 less than twice the number'. Translating the second quantity to mathetical expression would give you 2x-30. Equating the two quantity would give you 4x=2x-30, to solve for x, tranpose 2x to the left of the equal sign and combine like terms which will result to 4x-2x=-30, when simplified is 2x=-30. To eliminate the coefficient of x, divide both sides by 2, and would give you the final answer x=-30
Let x be the unknown number
4x=2x-30 (equation)
4x-2x=-30 (transpose 2x to the other side to be able to combine like terms)
2x=-30
2x/2=-30/2 (divide both sides by 2 to eliminate the coefficient of 2x)
x=-30
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