Question

Difficulty: EasySurds and Rationalization of Denominators

What is the simplified form of the expression 5018+8\sqrt{50} - \sqrt{18} + \sqrt{8}?

  1. 424\sqrt{2}Answer
  2. B
    2102\sqrt{10}
  3. C
    626\sqrt{2}
  4. D
    222\sqrt{2}

Answer

The simplified form of the expression is 424\sqrt{2}.
Simplifying each radical into basic surd form yields 50=52\sqrt{50} = 5\sqrt{2}, 18=32\sqrt{18} = 3\sqrt{2}, and 8=22\sqrt{8} = 2\sqrt{2}. Combining these like terms gives (53+2)2=42(5 - 3 + 2)\sqrt{2} = 4\sqrt{2}.

Step-by-Step Solution

1
Simplify each surd term into basic surd form
50=25×2=52\sqrt{50} = \sqrt{25 \times 2} = 5\sqrt{2}, 18=9×2=32\sqrt{18} = \sqrt{9 \times 2} = 3\sqrt{2}, and 8=4×2=22\sqrt{8} = \sqrt{4 \times 2} = 2\sqrt{2}
Converting each surd to have a common radicand allows for addition and subtraction of like terms.
2
Substitute the simplified surds back into the expression and combine like terms
5232+22=(53+2)2=425\sqrt{2} - 3\sqrt{2} + 2\sqrt{2} = (5 - 3 + 2)\sqrt{2} = 4\sqrt{2}
Surds with identical radicands can be combined by operating on their coefficients.

Key Concept

Simplification and Addition/Subtraction of Like Surds
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