Directions: Simplify, show all steps.


  1. $7(2 x+1)-2(3 x+4)$
  2. $2(x+3)+4(x-1)+10$



Applications:

  1. The sum of an unknown number and 15 can be represented by the expression $n+15$. Give a binomial expression, in simplest form, that represents three times this quantity.
  2. Eight times an unknown number which is then decreased by four is given by the expression $8 x-4$, where $x$ is the unknown number. Give an expression that represents one-fourth of this expression.

Verified Answer :

  • Problem 9 simplifies to \(\boxed{8x-1}\).
  • Problem 10 simplifies to \(\boxed{6x+12}\).
  • Problem 11 simplifies to \(\boxed{3n+45}\).
  • Problem 12 simplifies to \(\boxed{2x-1}\).

Explanation

  1. Simplifying Algebraic Expressions

The goal is to simplify various algebraic expressions using the distributive property and by combining like terms.

Problem 9: \(7(2x+1)-2(3x+4)\)
To simplify this expression, we apply the distributive property:
\(7(2x) + 7(1) - 2(3x) - 2(4) = 14x + 7 - 6x - 8\).
Next, we combine the like terms:
\((14x - 6x) + (7 - 8) = 8x - 1\).

Problem 10: \(2(x+3)+4(x-1)+10\)
Again, apply the distributive property:
\(2(x) + 2(3) + 4(x) - 4(1) + 10 = 2x + 6 + 4x - 4 + 10\).
Combining like terms gives:
\((2x + 4x) + (6 - 4 + 10) = 6x + 12\).

Problem 11: Represent three times the quantity \(n+15\).
We represent this as:
\(3(n+15) = 3(n) + 3(15) = 3n + 45\).

Problem 12: Represent one-fourth of the expression \(8x-4\).
We write this as:
\(\frac{1}{4}(8x-4) = \frac{1}{4}(8x) - \frac{1}{4}(4) = 2x - 1\).

Examples

Algebraic simplification is essential for modeling real-world scenarios. For example, if you are calculating the total cost of a shopping trip where you buy three shirts at \(\$n+15\) each, the expression \(3n+45\) quickly tells you your total cost. Similarly, if you have a budget of \(8x-4\) dollars for four different departments, dividing that total into equal shares for each department, represented by \(2x-1\), helps in efficient resource allocation. Mastering these steps ensures accuracy in daily financial planning and resource management.