Part 1
<h3>Answer: 13</h3>
---------------------
Explanation:
We'll replace every copy of x with -3. Then use PEMDAS to simplify.
f(x) = -2x+7
f(-3) = -2(-3)+7
f(-3) = 6+7
f(-3) = 13
===========================================================
Part 2
<h3>Answer: -11</h3>
---------------------
Explanation:
We work backwards in a sense compared to what part 1 did. Instead of finding f(x) based on x, we determine what x must be for a given f(x).
We'll replace f(x) with 29 and solve for x like so
f(x) = -2x+7
29 = -2x+7
-2x+7 = 29
-2x = 29-7
-2x = 22
x = 22/(-2)
x = -11
Note how if you replaced x with -11, we'd get,
f(x) = -2x+7
f(-11) = -2(-11)+7
f(-11) = 22+7
f(-11) = 29
which helps confirm we have the correct answer.
Answer:
The number of boys who play tennis is 36.
Step-by-step explanation:
Let the number of boys who play tennis is x.
number of boys who play cricket = y
x = 3 y..... (1)
12 boys plays both cricket and tennis.
According to the question,
x - 12 = y + 1 2
3 y - 12 = y + 12
2 y = 24
y = 12
So, the number of boys who plays tennis is x = 3 x 12 = 36.
Answer:
a) -3 gallons per hour
b) y = -3x +14
Step-by-step explanation:
Rate of change is computed by dividing the amount of change by the interval over which it occurred.
<h3>a)</h3>
Here the amount of gas decreased from 14 to 2 gallons, so a decrease of 14-2 = 12 gallons. That occurred over a 4-hour period, so the rate of change is (-12 gallons)/(4 hours) = -3 gallons/hour.
__
<h3>b)</h3>
The initial amount was 14 gallons, so the equation for the line describing remaining gas will be ...
y = -3x +14 . . . . gas in the tank after x hours
This is impossible and it is not even an equation since