Answer:
Step-by-step explanation:
7 a)
Step 1 :
Make the denominators the same
[tex]-\frac{1}{7} \ and \ \frac{2}{9}[/tex]
[tex]-\frac{1}{7} \times \frac{9}{9} = -\frac{9}{63}\\\\\frac{2}{9} \times \frac{7}{7} = \frac{14}{63}\\[/tex]
Step 2 :
Now find rational between (-9/63) and (14/63).
Just change the number in the numerator. Write any numbers between -9 and 14 in the numerator.
[tex]\frac{ -8}{63}, \ \frac{-7}{63},\ \frac{3}{63},\ \frac{6}{63},\ \frac{8}{63}[/tex]
7 b )
[tex]x = 3 + 2\sqrt2\\\\x + \frac{1}{x} = (3 + 2\sqrt2) + \frac{1}{3+2\sqrt2}[/tex]
[tex][ Rationalize \ the \ denominator : \frac{1}{3 + \sqrt2} \times \frac{3 - 2\sqrt2}{3-2\sqrt 2} = \frac{3 - 2 \sqrt2}{3^2 - (2 \sqrt2)^2 } = \frac{3 - 2\sqrt2}{9 - 8} = 3 - 2\sqrt 2 \ ][/tex]
[tex]therefore , x + \frac{1}{x} = 3 + 2\sqrt 2 + 3 - 2 \sqrt 2 = 6 + 0 = 6[/tex]
