Answer:
0.4077
Step-by-step explanation:
It's important to use parenthesis to avoid confusion.
9^(2x) = 6
Use exponent properties:
(9^2)^x = 6
81^x = 6
Take log of both sides
ln(81^x) = ln(6)
Use log properties:
x ln(81) = ln(6)
Solve for x:
x = ln(6) / ln(81)
x ≈ 0.4077
Get x all alone on its own side:
x=16+5
x=21
First we need to know how much each pen costs. So we take 11.77 and divide it by 11. That gives us 1.07 per pen. So answer choice A has 4 pens for 4.44, so we need to multiply 1.07 x 4. That gives you 4.28, so we know that isn't the correct answer. For option B, we need to multiply 1.07 x 5. That is 5.35, so that also can't be the answer. For C, we need to do 1.07 x 6, and that gives us 6.42. So we know the correct answer is option C.
Answer:
9.833333
Step-by-step explanation: