What is the value of x, when x2 + 5 = 21? A) 2 or -2 B) 4 or -4 C) 5.5 or -5.5 D) 8 or -8
2 answers:
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Answer:
a) 1/27
b) 16
c) 1/8
Step-by-step explanation:
a)
One of the properties of the exponents tells us that when we have a negative exponent we can express it in terms of its positive exponent by turning it into the denominator (and changing its sign), so we would have:
And now, solving for x = 9 we have:
b)
This is already a positive rational exponent so we are just going to substitute the value of y = 8 into the expression
c)
Using the same property we used in a) we have:
And now, solving for z = 16 we have:
to calculate the slope m , use the ' gradient formula '
m =
with (,
) = (0, - 1 ) and (
,
) = (1, 5 )
m = = 6
0