Answer:
Second option: 81y^4 - 16x^2, the difference of squares
Step-by-step explanation:
(9y^2-4x)(9y^2+4x) is a special product named difference of squares, then we can apply this formula:
(a-b)(a+b)=a^2-b^2, with a=9y^2 and b=4x, then:
(9y^2-4x)(9y^2+4x)=(9y^2)^2 - (4x)^2
(9y^2-4x)(9y^2+4x)=(9)^2 (y^2)^2 - (4)^2 (x)^2
(9y^2-4x)(9y^2+4x)=81y^(2*2) - 16x^2
(9y^2-4x)(9y^2+4x)=81y^4 - 16x^2
A.3n+4+3n+4+4n
=3n+3n+4n+4+4
=10n+8
B.11n+4+n-12
=11n+n+4-12
=12n-8
C.6(6n-2)
=36n-12
D.4(3n-2)
=12n-8
E.4n+22-12+8n
=4n+8n+22-12
=12n+10
so,B and D are the expressions that are equivalent to 12n-8.
Answer:
y=15x+185
Step-by-step explanation:
Step 1: Add -x to both sides.
x−5y+−x=−18+−x
−5y=−x−18
Step 2: Divide both sides by -5.
−5y−5=−x−18−5
y=15x+185
Answer:
In think the answer is 42,000
Step-by-step explanation:
Answer:
arc DB length = 14π feet
Step-by-step explanation:
Assuming point A is the center of the circle, arc DC has measure 180°. Arc DB has measure 40° less, so is 140°. Since you want this in terms of π, we need to convert the degree measure to radians. We do that by multiplying by (π/180) radians per degree:
arc DB = 140° = 140°(π/180°) radians
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Now that we know the arc measure in radians, we can find the length of the arc. It is given by the formula ...
s = rθ
where r represents the radius and θ is the measure of the arc in radians.
The arc length is ...
s = (18 ft)(7π/9) = 14π ft
Arc DB has a length of 14π feet.
