Answer:
Look at the description:
Step-by-step explanation:
The mistake is that they did not need to divide the radius by two since the radius is already half of the diameter. The area of a circle is pi*r^2. The second mistake they made was that they assigned pi the value of 3 which is wrong. After calculating, the area of the circle is 53^2pi = 8824.73mm^2
A) 6x + 4x - 6 = 24 + 9x
10x - 9x = 24 + 6
x = 30
b) 25 - 4x = 15 - 3x + 10 - x
25 - 4x = 25 - 4x
Infinite Solutions.
c) 4x + 8 = 2x + 7 + 2x - 20
4x - 4x = 7 - 20 - 8
0 = - 22
No solution
Answer:
Step-by-step explanation:
For quadratics, these formulas are used mainly for factoring.
Your equation can be written as ...
... 2(x² +2x -3) = 0
You factor this by looking for factors of -3 (c=x1·x2) that add to give +2 (b=-(x1+x2)). These are {-1, +3}, so the factorization is ...
... 2(x -1)(x +3) = 0
The roots are then 1 and -3, which sum to -b = -2.
(You will note that the numbers used in the binomial factors are the opposites of the roots x1 and x2 in the Viete's Formulas. That is how we can look for them to sum to "b", rather than "-b".)