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.
This question is super easy, all you need to do is isolate the y variable. When you want to isolate it, you have to get rid of other numbers by doing the opposite sign.
x+2y=8 Subtract the x.
2y=8-x Divide by two.
y=4-1/2x
-3y = x...so we sub in -3y for x in the other equation
-x + 7y = 70
-(-3y) + 7y = 70
3y + 7y = 70
10y = 70
y = 70/10
y = 7
so we sub in 7 for y in either of the original equations to find x
-3y = x
-3(7) = x
-21 = x
so ur solution is (-21,7)
<h2>1)</h2>
This must be true for some value of x, since we have a quantity squared yielding a positive number, and since the equation is of second degree,there must exist 2 real roots.
<h2>2)</h2>
Well he started off correct to the point of completing the square.
Answer: (n+5)x(n+1)
Step-by-step explanation:
1. Write 6n as a sum
2. Factor out n form the expression
3. Factor out n+5 from the expression
(n+5)x(n+1)
