F(x) = (1/2)x + 4
Plug y in for f(x).
y = (1/2)x + 4
Swap x and y.
x = (1/2)y + 4
Solve the equation for y =.
Subtract 4 from both sides.
x - 4 = (1/2)y
Multiply each term 2.
2x - 8 = y
Plug f^-1(x) in for y.
f^-1(x) = 2x - 8
f^-1(4) = 2(4) - 8
f^-1(4) = 0
Basically all the information in this problem is useless. They included all those numbers to confuse you. If you read throughly you can see that all you need to know is that Adam's sister can only have 70 grams of fat each day and that her dinner will have 48 grams of fat.
To figure this out I use this formula all the time to figure out percentages.
is/of=x/100
Your trying to figure out what is 48 percent of 70 because that's how much Adam's sister is going to eat at dinner. So your is would be 48 and your of is 70. When you substitute those numbers your formula becomes 48/70=x/100. Now you cross multiply and get 70x=4800.All that's left is to divide 70 on both sides. Which gives you 68.57.The final answer is 69 percent.
5-4 //jzbbxbxbzbbsjd jsjdjcn ñandú
