x = 7 and x = –7.
Solution:
Given data:
and
To find the solutions when f(x) = 64.
Both are equations of f(x), so equate the given equations, we get

To isolate the constant term subtract 15 from both sides.


49 can be written as 7².

Taking square root on both sides of the equation, we get
x = ±7
The solutions to f(x) = 64 is x = 7 and x = –7.
Jenna has $43 and Heidi has $17.
Step-by-step explanation:
Total amount = $60
Let,
Amount of Jenna = x
Amount of Heidi = y
According to given statement;
x+y=60 Eqn 1
x=2y+9 Eqn 2
Putting value of Eqn 2 in Eqn 1;

Dividing both sides by 3,

Putting y=17 in Eqn 2

Jenna has $43 and Heidi has $17.
Keywords: linear equations, substitution method
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Answer:
4
Step-by-step explanation:
Answer:
2.02
2.15
0.13
Step-by-step explanation:
Fastest time = smallest value = 2.02 secs
Slowest time = largest value = 2.15 secs
Range = largest value - smallest value = 2.15 - 2.02 = 0.13 secs
Find amount used:
Amount in the card = $20
Amount left = $13.28
Amount used = $20 - $13.28 = $6.72
Find duration of the call:
24 cents = 1 min
672 cents = 1/24 x 672 = 28 mins
Answer: The call was 28 minutes long.