Answer:
<em>He bought 6 hotdogs and 2 drinks</em>
Step-by-step explanation:
<u>System of Equations</u>
Kevin and his children went into a restaurant and bought $31.50 worth of hotdogs and drinks. Each hotdog costs $4.50 and each drink costs $2.25.
To solve the system of equations, we'll call the variables:
x = number of hotdogs
y = number of drinks
The first condition yields the equation:
4.50x + 2.25y = 31.50 [1]
It's also known he bought 3 times as many hotdogs as drinks, thus:
x = 3y [2}
Substituting [2] in [1]:
4.50(3y) + 2.25y = 31.50
Operating:
13.5y + 2.25y = 31.50
15.75y = 31.50
y = 31.50/15.75
y = 2
And
x = 3*2 = 6
He bought 6 hotdogs and 2 drinks
Equation of a line is in the form y = mx+c, where m is the gradient and c is the y-intercept.
First step is to find the gradient.
m = (y2-y1)/(x2-x1)
= ( 5- -8)/(8-4) = 13/4
We have y = (13/4)x + c
Now we replace one of the coordinates to find c. Let’s replace (4,-8)
We have: -8 = (13/4)*4 + c
-8=13+c
c=-8-13= -21
Therefore, equation of line is:
y = (13/4)x - 21
Answer:
3/4 of a foot will cost $2.25.
Step-by-step explanation:
This question is solved by rule of three, due to proportions.
One foot of lace costs 3 dollars. How much is 3/4 of a foot going to cost?
1 foot - 3 dollars
3/4 foot - x dollars
So
3/4 of a foot will cost $2.25.
Answer:
Domain of f(x): All real values.
Range of f(x): All real values.
Domain of f -1(x): All real values.
Range of f -1(x): All real values
Step-by-step explanation:
We are given the following function:
Since it is a line, we have that both the domain is the range is the real set.
Inverse function:
The domain of the inverse function is the range of the original function, and the range of the inverse function is the domain of the original function.
Finding the inverse function:
Exchange x and y in the original function, and isolate y. So
Original
Exchanging:
Isolating y: