SOLUTION: I need help with Converting this equation 6x+3y=4.5 into a function and find f(5). Please. Show steps so I may understand Thank you.

Algebra ->  Linear-equations -> SOLUTION: I need help with Converting this equation 6x+3y=4.5 into a function and find f(5). Please. Show steps so I may understand Thank you.      Log On


   

Question 177489: I need help with Converting this equation 6x+3y=4.5 into a function and find f(5). Please. Show steps so I may understand Thank you.
Found 2 solutions by Mathtut, jim_thompson5910:
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
well, its already a linear function. We do need to write it so as to isolate the y term.
:
3y=-6x+9/2
:
y=-2x+3/2
:
f(5)=-2x+3/2=-2(5)+3/2=-8.5

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

6x%2B3y=4.5 Start with the given equation.


3y=4.5-6x Subtract 6x from both sides.


3y=-6x%2B4.5 Rearrange the terms.


y=%28-6x%2B4.5%29%2F%283%29 Divide both sides by 3 to isolate y.


y=%28%28-6%29%2F%283%29%29x%2B%284.5%29%2F%283%29 Break up the fraction.


y=-2x%2B1.5 Divide.


f%28x%29=-2x%2B1.5 Now replace "y" with f(x). The equation is now in function form.


f%285%29=-2%285%29%2B1.5 Plug in x=5.


f%285%29=-10%2B1.5 Multiply -2 and 5 to get -10.


f%285%29=-8.5 Combine like terms.