I am so stuck on these Pre-Calculus problems! Can you help me?

Question

1.x(x+6)=9

2.(square root of x+2)+5=(square root of x+15)

3.(3x+4/3)-(2x/x-3)=x

4.5-(2/x)+(1/x^2)=0

5.x^-2/5 - 2x^-1/5 - 15=0

6.x^4-3x^2-4=0

7.(sixth root of 2x+1)=(sixth root of 9)

8.3[2x - (6-2x)+1]=5x

9.(14-2x)^2/3=4

10.(3/x-3)=(3/x-3) Can you please show work because I have answers in the back of the book, but I don't understand how they got there.

Answer 1

1.x(x+6)=9  distribute the x

x^2 + 6x = 9 subtract 9 from both sides

x^2 + 6x - 9  to solve this further, requires the quadratic eq.

2. sorry, don't know how to solve either

3.(3x+4/3)-(2x/x-3)=x  multiply everything by 3

9x + 4 - 6x/x-3 = 3x  now mult everything by x-3

9x^2 - 27x + 4x - 12 - 6x = 3x^2 - 9x sub 3x^2 and add 9x to both sides

6x^2 -20x - 12 = 0

3(3x^2 - 10x -6) = 0  again, requires quadratic eq to solve further.

6.x^4-3x^2-4=0

(x^2-4)(x^2 + 1)=0

x+2(x-2)(x^2 + 1)=0

x = -2 or 2 or i

3[2x - (6-2x)+1]=5x

6x - (18-6x) + 3 = 5x

6x - 18 + 6x + 3 = 5x

12x - 15 = 5x

7x=15

x= 15/7

10.(3/x-3)=(3/x-3)

x= anything.