Answer:
Option A is correct answer.
Step-by-step explanation:
An equation is having two sides equal. It has an = sign in it.
So, Option A 2y+7 = 9 is an equation as it has = sign in it. So, it is correct option.
All other options do not have = sign in them so, they are not equations.
(5r - 4)(r² - 6r + 4)
distributive property of multiplication.
5r(r² - 6r + 4) - 4(r² - 6r + 4)
5r³ - 30r² + 20r - 4r² + 24r - 16
group like terms and simplify.
5r³ - 30r² - 4r² + 20r + 24r - 16
5r³ - 34r² + 44r - 16 Choice A.
The surface of the water is 0 feet. So 10 feet down means it is 0 - 10, or -10 feet as its final position.
Answer:
6x + 3.25y = 42.50
x + y = 8
Step-by-step explanation:
x is the amount of drinks, and y represents the amount of candies that are bought. The first equation is used to figure out the amount of candies and drinks needed to be bought to add up to 42.50, and the second equation is used to make sure that the quantity of drinks and candies add up to 8.
The "rule of 72" says that the doubling time in years is approximately 72 divided by the interest rate in percent. To make the money grow by a factor of 4 requires that it double twice, so will take twice as long as the period to double once.
2×72/11.3 ≈ 12.7 . . . . years
_____
The "rule of 72" is an approximation. The actual quadrupling time for this interest rate and compounding is about 12.6 years. (The actual product of doubling time and nominal interest rate is about 71.25.)