Practice Evaluating Expressions in Two Variables

1. Evaluate ‍\(3 + jk + k^3\) when \(j = 2\) and ‍\(k = 6\).

2. Evaluate ‍\(8r -rs\) when \(r = 6\) and ‍\(s = 5\).

3. Evaluate ‍\(8 - \frac{m}{n} + p^2\) when \(m = 8\), \(n = 2\), \(p = 7\).

4. Evaluate ‍\( \frac{9}{g} +2h +5\) when \(g = 3\) and \(h = 6\).

Source: Khan Academy, https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:foundation-algebra/x2f8bb11595b61c86:substitute-evaluate-expression/e/evaluating_expressions_2
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

1. \(=231\)

2. \(=18\)

3. \(=53\)

4. \(=20\)

1. Let's substitute ‍\(j = 2\) and ‍\(k = 6\) into the expression.
   • \(3+jk+k^3\)
   • \(=3+(2)(6) + 6^3\)
   • \(=3+12+216\)

   • \(=231\)

2. Let's substitute ‍\(r = 6\) and ‍\(s = 5\) into the expression.
   • \(8r - rs\)
   • \(=8(6) - (6)(5)\)
   • \(=48-30\)

   • \(=18\)

3. Let's substitute ‍\(p = 7\), \(m = 8\) and ‍\(n = 2\) into the expression.
   • ‍\(8 - \frac{m}{n} + p^2\)
   • ‍\(=8 - \frac{8}{2} + 7^2\)
   • \(=8 - 4 + 49\)

   • \(=53\)

4. Let's substitute ‍\(g = 3\) and ‍\(h = 6\) into the expression.
   • \(\frac{9}{g} +2h +5\)
   • ‍\(=\frac{9}{3} +2(6) +5\)
   • \(=3+12+5\)

   • \(=20\)