Answer:
x = - 
, x = 3
Step-by-step explanation:
Given
(4x - 5)² = 49 ( take the square root of both sides )
4x - 5 = ± 
= ± 7 ( add 5 to both sides )
4x = 5 ± 7, thus
4x = 5 - 7 = - 2 ( divide both sides by 4 )
x = 
= -
or
4x = 5 + 7 = 12 ( divide both sides by 4 )
x = 3
As a check
Substitute these values into the left side of the equation and if equal to the right side then they are the solutions.
x = -
left side = (- 2 - 5)² = (- 7)² = 49 = right side ⇒ solution
x = 3
left side = (12 - 5)² = 7² = 49 = right side ⇒ solution
B = 16
explanation:
b-10 > 5
16-10 > 5
6 > 5
The other answer choices are less than or equal to 5
Plug in (4,64) into each answer choice.
A) 4(2)^x
64 =4(2)^4
64 = 4(16)
64 = 64
Answer choice A is correct.
B) f(x) = 2(4)^x
64 = 2(4)^4
64 = 2(256)
64 ≠ 512
Answer choice B is incorrect.
C) f(x) = 4(2)^{-x}
64 = 4(2)^{-4}
64 = 4(-0.0625)
64 ≠ 0.25
Answer choice C is incorrect.
D) f(x) = 2(4)^{-x}
64 = 2(4)^{-4}
64 = 2(0.00390625)
64 ≠ 0.0078125
Answer choice D is incorrect.
Your answer is B<span>) f(x)=2(4)^x</span>
0.4% can be written as 0.004 in decimal.
Step-by-step explanation:
Let the total amount she wants to save be 'a'
Starting amount = 0.4% of the total amount
= 0.4% of a
= (0.4/100) a
0.4% = 0.4/100
= 0.004
0.4% can be written as 0.004 in decimal.
