8 I don’t know how to explain but the answer is
8
Answer:
y = -1 + -0.75x
explanation:
Answer:
wait im sorry i tried to leave answering the question but accidently pressed add your question
Step-by-step explanation:
To find invers
1. solve for y
2. replace y with xinverse
so
x=4-4y+y^2
reorder right side
x=y^2-4y+4
factor right side
x=(y-2)^2
squaer root both sides
+/-√x=y-2
add 2 to both sides
2+/-√x=y
switch x and y
2+/-√y=xinverse
xinverse=2+√y or 2-√y
subtract 4 from both sides
C) (0.85 + x/100)(250+145) does not give the correct answer.
Explanation
A) works; adding the two costs together is 250+145=395. We multiply this by 0.85 because 100%-15%=85%=0.85. We also have x% tax, which is represented by x/100, added to 100% of the value, or 1.00. Altogether this gives us
395(0.85)(1+x/100) = 395(0.85 + (0.85x/100)) = 395(0.85) + 395(0.85x/100)
= 395(0.85) + 395(0.0085x)
B) works; we have 250+145 for the original price; we have 85% = 0.85 of the value; we also have 100% + x%, which is (100+x)/100.
C) does not work; (0.85+x/100)(395) does not take into consideration that you are finding the tax after taking the 85%. This will simplify out to
0.85*395 + (x/100)(395) = 335.75 + 395x/100 = 335.75 + 3.95x, which is too much.
D) works; simplifying the expression from A, we have 395(0.85) + 395(0.0085x) = 335.75 + 3.3575x.
