See https://web2.0calc.com/questions/i-need-help_4982.
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Evaluate the expression 4(2x+y)-2y+z for x=-2, y=4 and z=-3
Before inserting the values of the variables, I recommend writing the equation in its simplest form.
First, use the distributive property and distribute 4:-
8x+4y-2y+z
Simplifying,
8x+2y+z
Now that the expression is in its simplest form, we can substitute the variables and simplify the expression.
First, write -2 in lieu of x:-
8(-2)+2y+z
-16+2y+z
Now, write 4 in lieu of y:-
-16+2(4)+z
-16+8+z
-8+z
Final step:-
write -3 in lieu of z:-
-8+(-3)
-8-3
-11
<h3>Good luck.</h3>
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Formula
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d = r * t
Givens
======
d = 2 3/4
t = 1 hour 15 minutes
r = ????
Calculations
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You need to convert the 15 minutes to hours.
1 hour = 60 minutes
x hour = 15 minutes
1/60 = x/15
x = 15/60
x = 0.25 hours
so the time = 1 hours + 0.25 hours
t = 1.25 hours
Now you need to do something with the distance.
3/4 mile = 0.75 of a mile
So the distance = 2 + 0.75 = 2.75 miles
Now you are ready for the answer.
d = r * t you are looking for r
2.75 = r * 1.25
r = 2.75/1.25
r = 2.2 miles / hour
Note you could do this with fractions.
2 3/4 = 11/4
1 1/4 = 5/4
r = 11/4 // 5/4 =11/5 = 2 1/5 which is the same thing as 2.2. If your calculator can handle fractions (those kind of calculators cost about 10 dollars in Canada. It should be 8 in the US) that might be the way to do this problem.
Answer:
m is slope. slope is where it touches the y-axis so it would be "0"
f(-9) means x is -9
Replace x with -9 and solve:
2/3(-9) - 6
Simplify:
-6 - 6 = -12
f(-9) = -12
