Answer:
3
Step-by-step explanation:
The square root of 9 is 3
Answer: 
Step-by-step explanation:
We know that the standard quadratic equation is ax^2+bx+c=0
Let's compare all the given equation to it and , find discriminant.
1. a=2, b= -7, c=-9
So it has 2 real number solutions.
2. a=1, b=-4, c=4

So it has only 1 real number solution.
3. a=4, b=-3, c=-1

So it has 2 real number solutions.
4. a=1, b=-2, c=-8
So it has 2 real number solutions.
5. a=3, b=5, c=3

Thus it does not has real solutions.
B - 7x = a - b
Subtract b from both sides.
-7x = a - 2b
Divide both sides by -7.
x =
We sketch two triangles, DFE and DGH, as shown below
Side DF correspond to side DG, the scale factor is 40÷32=1.25
Side DE correspond to side DH, the scale factor is 30÷24=1.25
That leaves us with the last corresponding sides, EF and HG which would also have a scale factor 1.25
Both triangles share the same angle D
We can conclude triangle DFE and triangle DGH are similar for property SSS and SAS