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Simplify each of the following expressions:

(√5-√12)²
(√12+√11)²
(√6+√7) (√6-√7)
Rationalize
1/√8
1/√7-√1
1√8+3

User Imthi
by
7.3k points

1 Answer

1 vote

Simplifying each of the following expressions:

a) (√5-√12)²:

First, we can simplify the square of each term using the formula (a-b)² = a² - 2ab + b²:

(√5-√12)² = (√5)² - 2(√5)(√12) + (√12)²

= 5 - 2√60 + 12

Next, we can simplify √60 by factoring out its largest perfect square factor, which is 4:

5 - 2√60 + 12 = 17 - 2√(4*15) = 17 - 4√15

Therefore, (√5-√12)² = 17 - 4√15.

b) (√12+√11)²:

We can simplify this expression using the same formula as before:

(√12+√11)² = (√12)² + 2(√12)(√11) + (√11)²

= 12 + 2√132 + 11

Next, we can simplify √132 by factoring out its largest perfect square factor, which is 4:

12 + 2√132 + 11 = 23 + 2√(4*33) = 23 + 2√132

Therefore, (√12+√11)² = 23 + 2√132.

c) (√6+√7) (√6-√7):

This expression can be simplified using the difference of squares formula, (a-b)(a+b) = a² - b²:

(√6+√7) (√6-√7) = (√6)² - (√7)²

= 6 - 7

= -1

Therefore, (√6+√7) (√6-√7) = -1.

Rationalizing each of the following expressions:

a) 1/√8:

To rationalize the denominator, we can multiply both the numerator and denominator by √8:

1/√8 = (1/√8) * (√8/√8) = √8/8

Therefore, 1/√8 = √8/8.

b) 1/√7-√1:

To rationalize the denominator, we can multiply both the numerator and denominator by the conjugate of the denominator, which is √7+√1:

1/√7-√1 = (1/√7-√1) * (√7+√1)/(√7+√1) = (√7+√1)/(7-1)

= (√7+√1)/6

Therefore, 1/√7-√1 = (√7+√1)/6.

c) 1/√8+3:

To rationalize the denominator, we can multiply both the numerator and denominator by the conjugate of the denominator, which is √8-3:

1/√8+3 = (1/√8+3) * (√8-3)/(√8-3) = (√8-3)/(8-9)

= -(√8-3)

Next, we can simplify √8 by factoring out its largest perfect square factor, which is 4:

-(√8-3) = -

User Fobos
by
8.4k points
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