Answer:
)x + 5)(x - 5)
Step-by-step explanation:
x² - 25 ← is a difference of squares and factors in general as
a² - b² = (a + b)(a - b), thus
x² - 25 = x² - 5² = (x + 5)(x - 5)
You could simplify this work by factoring "3" out of all four terms, as follows:
3(x^2 + 2x - 3) =3(0) = 0
Hold the 3 for later re-insertion. Focus on "completing the square" of x^2 + 2x - 3.
1. Take the coefficient (2) of x and halve it: 2 divided by 2 is 1
2. Square this result: 1^2 = 1
3. Add this result (1) to x^2 + 2x, holding the "-3" for later:
x^2 +2x
4 Subtract (1) from x^2 + 2x + 1: x^2 + 2x + 1 -3 -1 = 0,
or x^2 + 2x + 1 - 4 = 0
5. Simplify, remembering that x^2 + 2x + 1 is a perfect square:
(x+1)^2 - 4 = 0
We have "completed the square." We can stop here. or, we could solve for x: one way would be to factor the left side:
[(x+1)-2][(x+1)+2]=0 The solutions would then be:
x+1-2=0=> x-1=0, or x=1, and
x+1 +2 = 0 => x+3=0, or x=-3. (you were not asked to do this).
The correct answer is the first one.
5 x 100 is correct.
9 x 1 is correct because the 9 is in the ones section, not the tens.
3 x 1/10 is correct because it is equal to 0.3.
7 x 1/1000 is correct because it is equal to 0.007.
Hope this helped! You’re welcome
Answer:
statement: 2. both pairs of parallel lines are congruent
reason: 2. def. of a parallelogram
and that should be all you need
Answer:
20.25π
Step-by-step explanation:
The circumference (C) of a circle is calculated using the formula
C = 2πr ← r is the radius
given C = 9π, then
2πr = 9π ( divide both sides by 2π )
r = 
( cancel the π on numerator/denominator )
= 4.5
The area (A) of a circle is calculated using the formula
A = πr² = π × 4.5² = 20.25π
