So this is a difference of 2 perfect squares
so if
x^2-y^2 then it is equal to (x-y)(x+y)
so
x^4-81=[(x^2)^2]-[(9)^2]=(x^2-9)(x^2+9)
so we know if xy=0 then x or/and y=0 so assume that they are equal to zero
x^2+9=0
we can't do anything about this because
x^2=-9
and that is not possible in the real realm
x^2-9=0
yet another difference of 2 perfect squares
x^2-3^2=(x-3)(x+3)=0
set them to zero
x-3=0
x=3
x+3=0
x=-3
so x=3 or -3
Answer: Probably C
Step-by-step explanation:
Answer:
134.4 centimeters
Step-by-step explanation:
This question is asking us for a missing leg on the triangle, lets call it x. Using the Pythagorean theorem (a²+b²=c²), we can figure out what value is missing (either a or b, they are interchangeable).
replace the values in the equation.
83²+x²=158²
get rid of the exponents.
6,889+ x² = 24,964.
subtract 6,889 from 24,964.
x²=18,075.
find the square root on both sides of the equation.
x=134.4432966.
I am assuming you want this rounded to the nearest tenth.
134.4 is your answer.
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