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Set up the equation for the following word problem and solve the equation. Let z be the unknown number.51 times the difference between a number and 21 is equal to the number plus 58.

User PinkiNice
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1 Answer

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You have the following sentence:

51 times the difference between a number and 21 is equal to the number plus 58.​

The previous expression can be written in an algebraic way as follow:

If z is the unknown number, you have:


51\cdot(z-21)=z+58

In order to solve the previous expression, proceed as follow:

- Expand parenthesis left side:


51z-1071=z+58

- Next, subtract z both sides and add 1071 both sides:


51z-z=58+1071

- Simplify like terms;


50z=1129

- Divide by 50 both sides:


z=(1129)/(50)\approx22.58

Hence, the value of z is 1129/50, or approximately 22.58

User Ben Lachman
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