The amount of simple interest accrued on a sum of money varies jointly with the amount of money, the interest rate, and the time the money is invested. a sum of money is invested at 4% for 3 years and accrues $168 in interest. the same sum of money is invested in a second account at 6% for 4 years. which statement is true?

which is the answer?

a )the amount of interest accrued on the second account is less than double the amount of interest accrued on the first account.

b )the amount of interest accrued on the second account is double the amount of interest accrued on the first account.

c ) the amount of interest accrued on the second account is more than double but less than triple the interest on the first account.

d ) the amount of interest accrued on the second account is more than triple the interest accrued on the first account.

B )The amount of interest accrued on the second account is double the amount of interest accrued on the first account.

Step-by-step explanation:

A sum of money is invested at 4% for 3 years and accrues $168 in interest.

Lets find the principle.

The formula for simple interest is =

p = ?

i = 168

r = 4%

t = 3

Now putting these values in the formula;

p = $1400

The same sum of money is invested in a second account at 6% for 4 years.

So, interest will be =

I = $336

Difference between both interests = dollars

We can see, that the second account gives double amount of $168.

Now, the true statement is :

B )The amount of interest accrued on the second account is double the amount of interest accrued on the first account.

starting with:    

5 + x - 12 = 2x - 7   

5 + x - 12 - x = 2x - 7 - x (subtract x from both sides)   

5 - 12 = x - 7 (combine and cancel x's from both sides)   

5 - 12 + 7 = x - 7 + 7 (add 7 to both sides)   

0 = x (add numbers together on both sides)       

so in order for the equation to be true, x must be 0.   

trying x = -0.5   

5 + x - 12 = 2x - 7 (original equation)   

5 + -0.5 - 12 = 2(-0.5) - 7 (plug in value of x)   

5 + -0.5 - 12 = -1 - 7 (did multiplication)   

-7.5 = -8 (did addition on both sides)       

since -7.5 is obviously not equal to -8, the value of -0.5 for x is wrong.   

trying x = 0   

5 + x - 12 = 2x - 7 (original equation)   

5 + 0 - 12 = 2(0) - 7 (plug in value of x)   

5 + 0 - 12 = 0 - 7 (did multiplication)   

-7 = -7 (did addition on both sides)       

since -7 equals -7, that demonstrates that the value of 0 for x is correct.   

trying x = 1   

5 + x - 12 = 2x - 7 (original equation)   

5 + 1 - 12 = 2(1) - 7 (plug in value of x)   

5 + 1 - 12 = 2 - 7 (did multiplication)   

-6 = -5 (did addition on both sides)       

since -6 is obviously not equal to -5, the value of 1 for x is wrong.