Answers to exercises

Exercise 1

$x+y$

Exercise 2

$x^n-1$

Exercise 3

Both sides equal $a^2b+a^2c+ab^2+2abc+b^2c+ac^2+bc^2$.

Exercise 4

$(4x^2-1)(x-3)$; $x=\pm \frac{1}{2}$, $x=3$

Exercise 5

$(a-b)(a+b)^3$

Exercise 6

$\dfrac{-13x}{(x + 1)(x + 2)(x + 3)}$

Exercise 7

$x=2$

Exercise 8

$(x-1)^2+(y-3)^2=11$, centre $(1,3)$, radius $\sqrt{11}$.

Exercise 9

$x=2$, $y=4$ or $x=-1$, $y=1$.

Exercise 10

$n= \dfrac{\log(\frac{A}{P})}{\log(1+R)}$