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2 years ago

Rachel is calculating the interest earned on a deposit of $350 in an account that earns 6% simple interest after 15 years.

Mathematics

2 answers:

alukav5142 [94]2 years ago

8 0

Answer:

$315

Step-by-step explanation:

You are going to want to use the simple interest formula for this. The one below is modified for solving the interest earned.

I = interest amount

P = principal amount

r = interest rate (decimal form)

t = time

Now we can plug in the values into the equation:

This means that Rachel earned $315 worth of interest in the 15 year period.

vlada-n [284]2 years ago

5 0

Answer: $315

Step-by-step explanation:

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Is 0.33 greater than 0.3333333333333

34kurt

No it's not_______________

7 0

3 years ago

For which system of equations is (5, 3) the solution? A. 3x – 2y = 9 3x + 2y = 14 B. x – y = –2 4x – 3y = 11 C. –2x – y = –13 x

Alla [95]

The correct answer is:

D) $\left \{ {{2x-y=7} \atop {2x+7y=31}} \right.$ .

Explanation:

We solve each system to find the correct answer.

For A:
$\left \{ {{3x-2y=9} \atop {3x+2y=14}} \right.$

Since we have the coefficients of both variables the same, we will use elimination to solve this.

Since the coefficients of y are -2 and 2, we can add the equations to solve, since -2+2=0 and cancels the y variable:
$\left \{ {{3x-2y=9} \atop {+(3x+2y=14)}} \right. 
\\
\\6x=23$

Next we divide both sides by 6:
6x/6 = 23/6
x = 23/6

This is not the x-coordinate of the answer we are looking for, so A is not correct.

For B:
$\left \{ {{x-y=-2} \atop {4x-3y=11}} \right.$

For this equation, it will be easier to isolate a variable and use substitution, since the coefficient of both x and y in the first equation is 1:
x-y=-2

Add y to both sides:
x-y+y=-2+y
x=-2+y

We now substitute this in place of x in the second equation:
4x-3y=11
4(-2+y)-3y=11

Using the distributive property, we have:
4(-2)+4(y)-3y=11
-8+4y-3y=11

Combining like terms, we have:
-8+y=11

Add 8 to each side:
-8+y+8=11+8
y=19

This is not the y-coordinate of the answer we're looking for, so B is not correct.

For C:
Since the coefficient of x in the second equation is 1, we will use substitution again.

x+2y=-11

To isolate x, subtract 2y from each side:
x+2y-2y=-11-2y
x=-11-2y

Now substitute this in place of x in the first equation:
-2x-y=-13
-2(-11-2y)-y=-13

Using the distributive property, we have:
-2(-11)-2(-2y)-y=-13
22+4y-y=-13

Combining like terms:
22+3y=-13

Subtract 22 from each side:
22+3y-22=-13-22
3y=-35

Divide both sides by 3:
3y/3 = -35/3
y = -35/3

This is not the y-coordinate of the answer we're looking for, so C is not correct.

For D:
Since the coefficients of x are the same in each equation, we will use elimination. We have 2x in each equation; to eliminate this, we will subtract, since 2x-2x=0:

$\left \{ {{2x-y=7} \atop {-(2x+7y=31)}} \right. 
\\
\\-8y=-24$

Divide both sides by -8:
-8y/-8 = -24/-8
y=3

The y-coordinate is correct; next we check the x-coordinate Substitute the value for y into the first equation:
2x-y=7
2x-3=7

Add 3 to each side:
2x-3+3=7+3
2x=10

Divide each side by 2:
2x/2=10/2
x=5

This gives us the x- and y-coordinate we need, so D is the correct answer.

7 0

3 years ago

Name a pair of perpendicular lines: is line BC and AJ perpendicular: explain

wel

A pair of perpendicular lines would be line CF and line AJ.

Line BC and line AJ are NOT perpendicular because when a pair of lines are perpendicular, all angles become 90 degrees. It is obvious, in the case, if you were to slide line BC on top of line AJ, the angles will not equal 90 degrees.

8 0

3 years ago

1/2x+1/3y=5 and 1/4x+y=10 solve this system by substitution

qaws [65]

Answer:

(x, y) = (4, 9)

Step-by-step explanation:

You can use the second equation to write an expression for y.

y = 10 - 1/4x . . . . subtract 1/4x from the given 2nd equation

Now, substitute that for y in the first equation:

1/2x + 1/3(10 -1/4x) = 5

1/2x + 10/3 -1/12x = 5 . . . . eliminate parentheses

You can work this a couple of ways from here. One is to multiply by 12 to eliminate fractions. Another is to work with the numbers as they are. We'll do that, because we don't get enough practice doing arithmetic with fractions.

5/12x = 5/3 . . . . . subtract 10/3

x = (5/3)/(5/12) = 12/3 = 4

From above, we can use our expression for y:

y = 10 - 1/4·4 = 9

The solution is (x, y) = (4, 9).

5 0

3 years ago

Which one is bigger, 0.75 or 0.4?

lions [1.4K]

Answer:

0.75

Step-by-step explanation:

0.75 is 3/4th of 1. 0.4 is 4/10 = 2/5 (40%) of 1. 75 is bigger than 40.

3 0

3 years ago

Read 2 more answers