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3 years ago

Given that 2x-7y=30

Mathematics

1 answer:

lidiya [134]3 years ago

4 0

Answer:

y = - $\frac{24}{7}$

Step-by-step explanation:

Substitute x = - 3 into the expression

2x - 7y = 30

2(- 3) - 7y = 30

- 6 - 7y = 30 ( add 6 to both sides )

- 7y = 36 ( divide both sides by - 7 )

y = $\frac{36}{-7}$ = - $\frac{36}{7}$

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? For which value of x is the inequality 45 - 4x < 14 true?

viktelen [127]

Answer:

7.75

Step-by-step explanation:

You group like terms from the inequality above ie by making the x value stands alone and you can only do this by sending 14 to the left side of the inequality and 4x to the right side. This becomes 45-14 < 4x and that gives you 31 < 4x. Then you divide both side by the number attached to the variable 'x' ie 4. So 31/4 < 4x/4 making x > 31/4 which is 7.75

8 0

3 years ago

PLZZZZZ NEED HELP!!!!!!

mylen [45]

Remember the rules of Sohcahtoa (Sine, cosine, tangent). For this problem we take the cosine of 38 because the labeled sides are the adjacent leg and the hypotenuse.

Cos(38)=79/x

Cosine of 38 is about 0.7880

0.7880=79/x

Next we multiply both sides by the denominator

(x) 0.7880=79 (x)

Then divide.

0.7880x= 79

0.7880 0.7880

X=100.25

Hope this helped :)

5 0

3 years ago

Suppose payments were made at the end of each month into an ordinary annuity earning interest at the rate of 4.5%/year compounde

valentina_108 [34]

Answer:

each payment = $214.20

Step-by-step explanation:

For ordinary annuity,

FVOA = PMT x [{(1+r/m)^(n*m)} - 1/(r/m)]

Here, FVOA = $50,000

year, n = 14

Since the interest will be paid monthly, m = 12

interest rate, r = 4.5% = 0.045

PMT = ?

Putting all the values into the ordinary annuity formula,

FVOA = PMT x [{(1+r/m)^(n*m)} - 1/(r/m)]

$50,000 = PMT x [{(1+0.045/12) ^ (14*12)} - 1/(0.045/12)]

or, $50,000 = PMT x [{(1+0.045/12) ^ (14*12)} - 1/(0.045/12)]

or, $50,000 = PMT x [(1.8754 - 1)/0.00375]

or, $50,000 = PMT x 233.4399

or, PMT = $50,000/233.4399

PMT = $214.19

or, monthly payment will be $214.20 (Nearest cent)

7 0

3 years ago

35 solve the following syste

blondinia [14]

Part A: The solution is $(-0.923,5.692)$

Part B: The point $(3,7)$ is not in the solution set.

Explanation:

Part A: The given inequalities are $3 x+4 y>20$ and $x$

The solution can be determined by solving the two inequalities by substitution method.

Changing inequalities to equality, we have,

$x=3 y-18$ and $3 x+4 y=20$

Let us substitute $x=3 y-18$ in the equation $3 x+4 y=20$ , we get,

$3 (3y-18)+4 y=20$

$9y-54+4y=20$

$13y=74$

$y=5.692$

Substituting $y=5.692$ in $x=3 y-18$ , we get,

$x=3 (5.692)-18$

$=17.076-18$

$x=-0.923$

Thus, the solution set is $(-0.923,5.692)$

Part B: Now, we shall determine whether the point $(3,7)$ is in the solution set.

Let us substitute the point $(3,7)$ in the inequalities $3 x+4 y>20$ and $x$ , we get,

$3 (3)+4 (7)>20$

$9+28>20$

$37>20$

Also, substituting $(3,7)$ in $x$ , we get,

$3$

Since, the point $(3,7)$ does not satisfy one of the inequality $x$ , the solution set does not contain the point $(3,7)$

Thus, the point $(3,7)$ is not in the solution set.

8 0

3 years ago

Seven less than one-fourth of a number is 2. What is the number?

insens350 [35]

Based on the equation given, it can be deduced that the value of the number will be 36.

Let the number be represented by x

Therefore, seven less than one-fourth of a number will be:

=(1/4 × x) - 7

= 0.25x - 7

Now, seven less than one-fourth of a number is 2 will be written as:

0.25x - 7 = 2

0.25x = 2 + 7

0.25x = 9

x = 9/0.25

x = 36

Learn more about equation on:

brainly.com/question/13802812

6 0

2 years ago