Answer:

or

Step-by-step explanation:
Hello!
Use the quadratic formula: 
First, let's convert our equation to standard form of a Quadratic: ax² + bx + c = 0
3x² = 80
3x² - 80 = 0
Note, thats the value of b will be 0, as there is no "bx"
Now, solve:
Plug in values
Simplify the radical (Discriminant)
Pull out perfect squares
Reduce factors
The solutions are 
Answer:
9
Step-by-step explanation:
3y = 27x
We want to find k when y = kx
Divide each side by 3
3y/3 = 27x/3
y = 9x
The constant of proportionality is 9
Answer: x=7
ab=21
bc=14
Step-by-step explanation:
ab=3x
bc=2x±7
ac=42
3x±2x±7=42
5x±7=42
5x=42-7
5x=35
to get the value of x you divide 35 by 5x
35÷5x=7
so the value of x is 7
ab=3x
x=7
3x=7×3x
7×3=21
x=7
2x=7×2x
2×7=14
Answer:
105
Step-by-step explanation:
Let the angle of B be x
According to the question,
5x+x=90
or, 6x=90
or, x=15
The angle of B is 15
The angle of A is (15*5)=75
The supplementary angle of A is
(180-75)=105
I don’t get want u need help with.