Coulld someone take the time and check my answers please.

Question

11) without graphing is the system independent, dependent, or inconsistent?
y=-x+5
-3x-3y=-15

(my answer; dependent)

12) your club is baking vanilla and chocolate cakes for a bake sale. they need at most 19 cakes you cannot have more than 14 chocolate cakes. write and graph a systme of inequalities to model this system.

(my answer;
let x=the number of vanilla cakes
let y=the number of chocolate cakes
x>=0
y>=0
x+y<=19
y<=14)

13)which matrix represents the system of equations below?
-12x-13y+13z=15
7x-10y-3x=11
7x+14y+5z=-5

(my answer;
-12 -13 13 15
7 -10 -3 11
7 14 5 -5)

14) which graph represents y=3(x-3)^2+3

(my answer; go over 3units to right up 3 and make a u shape upward)

16)what is the equation in standard form of a parabola that models the values in the table?
x -2 0 4
f(x) 4 -6 70

(possible answers)
y=3x^2+4x-6
y=4x^2+3x-6
y=6x^2+3x-4
y=-4x^2-3x+6
didnt understand this one

17) what value completes the square for the expression.
x^2-12x

(my answer; 36)

18) Use the quadratic formula to solve the equation.
-x^2+7x=8

(my answer; 7/2 +- sqrt34/2)

19)simplify the expression.
(-6i)(-4i)

(my answer; -24)

20) use graphing to find the solutions to the system of equations
y=-x^2-5x+3
y=-x-2

(my answer; (-5,3)(1,-3)

21) classify 5x^5+3x^4-8x^3+12 by number of terms.

(my answer; polynomial of 5 terms)

22) what are the zeros of the function graph the function
y=(x+3)(x+2)(x-2)

(my answer; -3,-2,2 graph upside down u on left bottom and straight line up and down on right side

23)find the real solutions of the equation
-8x^3-17x^2+7x=0

(didnt understand possible choices
0,-2.48,0.35
-2.48
-2.48,0.35
0.248,-0.35)

24) find the rational roots of
x^4+8x^3+7x^2-40x-60=0

(my answer; -6,-2)

25) find all the zeroes of the equation
27x^2-324=x^4

(my answer; 3,-3,6i,-6i)

Any help or explanations is helpful have an exam coming up and trying to review

Answer 1

11) dependent
12) Correct
13) Correct
14) Correct
16) y=4x^2+3x-6
17) 36
18) 7/2 ± √34/2
19) 24
20) (-5,3) (1,-3)
21) Polynomial of 5 terms
22) -3,-2,2
23) -2.48, 0.35
24) -6, -2
25) 3, -3, 6i, -6i