Answer: A
Step-by-step explanation:
2x²-2x-9=0
this is a quadratic equation so we will use the quadratic formula .
Δ= b²-4*a*c
let's calculate Δ to khow how many solutions this equations have .
Δ= (-2)²-4*2*(-9)
= 76
we notice that 76>0
so this equation has two solutions : (-b-√76)/4 and (-b+√76)/4
- let's calculte the values :
- (-b-√76)/4=
(-b+√76)/4=
the trick here is to notice that :
= 
= 
= 2
Now we will simplify Δ by factoring by 2
= 
so the answer is a .
Answer:
9x^2 - 3x - 30
Step-by-step explanation:
3x l 5
3x l 9x^2 l 15x
l ----- l ------
-6 l -18x l -30
Answer:
x=30
Step-by-step explanation:
5x+x=180
6x=180
x=30
5x=150
x=30
3x=90
2x=60
Answer:
As shown in picture, the area is divided into 4 parts: 3 triangles and 1 rectangles.
Total area:
A = smallest triangle + medium triangle + largest triangle + rectangle
= 2 x 2 x 1/2 + 2 x 6 x 1/2 + 4 x (2 + 2 + 6) x 1/2 + 2 x 2
= 2 + 6 + 20 + 4
= 32
Hope this helps!
:)
“Extraneous solutions are not solutions at all. They arise from outside the problem, from the method of solution. They are extraneous because they are not solutions of the original problem. ... To tell if a "solution" is extraneous you need to go back to the original problem and check to see if it is actually a solution.”
Basically, they are an answer you get when you solve a problem, but they don’t actually make the equation true so you disregard it.
