SOLUTION: Simplify the expression. 1a) square root of 54 1b)square root of 72 1c) square root of 5/9 1d) square root of 7/36 1e) square root of 9/11 1f)square root of 9/25

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Simplify the expression. 1a) square root of 54 1b)square root of 72 1c) square root of 5/9 1d) square root of 7/36 1e) square root of 9/11 1f)square root of 9/25      Log On


   



Question 118551: Simplify the expression.
1a) square root of 54
1b)square root of 72
1c) square root of 5/9
1d) square root of 7/36
1e) square root of 9/11
1f)square root of 9/25

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
I'll do the first three to show you how to do these problems

1a)

sqrt%2854%29 Start with the given expression

The goal of simplifying expressions with square roots is to factor the radicand into a product of two numbers. One of these two numbers must be a perfect square. When you take the square root of this perfect square, you will get a rational number.
So let's list the factors of 54
Factors:
1, 2, 3, 6, 9, 18, 27, 54


Notice how 9 is the largest perfect square, so lets factor 54 into 9*6


sqrt%289%2A6%29 Factor 54 into 9*6

sqrt%289%29%2Asqrt%286%29 Break up the square roots using the identity sqrt%28x%2Ay%29=sqrt%28x%29%2Asqrt%28y%29

3%2Asqrt%286%29 Take the square root of the perfect square 9 to get 3

So the expression sqrt%2854%29 simplifies to 3%2Asqrt%286%29

----------------------------
Check:
Notice if we evaluate the square root of 54 with a calculator we get

sqrt%2854%29=7.34846922834953

and if we evaluate 3%2Asqrt%286%29 we get

3%2Asqrt%286%29=7.34846922834953

This shows that sqrt%2854%29=3%2Asqrt%286%29. So this verifies our answer





1b)

sqrt%2872%29 Start with the given expression

The goal of simplifying expressions with square roots is to factor the radicand into a product of two numbers. One of these two numbers must be a perfect square. When you take the square root of this perfect square, you will get a rational number.
So let's list the factors of 72
Factors:
1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72


Notice how 36 is the largest perfect square, so lets factor 72 into 36*2


sqrt%2836%2A2%29 Factor 72 into 36*2

sqrt%2836%29%2Asqrt%282%29 Break up the square roots using the identity sqrt%28x%2Ay%29=sqrt%28x%29%2Asqrt%28y%29

6%2Asqrt%282%29 Take the square root of the perfect square 36 to get 6

So the expression sqrt%2872%29 simplifies to 6%2Asqrt%282%29

----------------------------
Check:
Notice if we evaluate the square root of 72 with a calculator we get

sqrt%2872%29=8.48528137423857

and if we evaluate 6%2Asqrt%282%29 we get

6%2Asqrt%282%29=8.48528137423857

This shows that sqrt%2872%29=6%2Asqrt%282%29. So this verifies our answer





1c)

sqrt%285%2F9%29 Start with the given expression


sqrt%285%29%2Fsqrt%289%29 Break up the fraction


sqrt%285%29%2F3 Take the square root of 9 to get 3


So sqrt%285%2F9%29 simplifies to sqrt%285%29%2F3