Answer:
number 1: {0,-6) number 2: f(-2)=25 number 3: x=±10 number 4:B, or x=-2, x=3
number 5:36 i really hope this helps! have a good day!
Step-by-step explanation:
1: 2x^2+12x +0=0
this is how you set it up
next, you have to find the a,b,and c. This is my personal favorite way of doing this.
a=2 b=12, c=0
you plug it in to the quadratic formula which is
-b±√b^2-4ac/2a
(-12)±√(12)^2-4(2)(0)/2(2)
next you have to simplify
-12±√144-0/4
take the square root of 144
-12±12/4-
then, find the solutions of them
-12+12=0
0/4=0
x=0
we are not done yet
-12-12=-24
-24/4
x=-6
your solutions are 0,-6, which is C
2: it is giving us x, which is -2
plug in -2 to the right side of the equation.
2(-2)^2-4(-2)+9
2(4)-8+9
8-8+9
f(-2)=9
3: this one is fairly simple
x^2=100
take the square root of each side
x=±10
4: you have to replace y for 0 in this one
x^2-x-6=0
all you have to do is factor it out, and it turns into
(x+2)(x-3)
then turn these so they equal 0
x+2=0, x-3=0
x=-2 x=3
your answer would be B
5: this one is fairly simple too
the formula to completing the square is (b/2)^2
you plug in b, which is 12
12/2=6
6^2=36
you would add 36 to each side.
