Is this a valid argument?

Pleaseeee i will mark brainlesttttt solve this system of equations 12x−15y=14 8x−15y=6

Sphinxa [80]

Answer:

x = 2 and y = $\frac{2}{3}$

Step-by-step explanation:

To solve this system of equation, we will follow the steps below;

We will use both elimination and substitution method to solve this system of equations

12x−15y=14 ------------------------------------------------------------------------(1)

8x−15y=6 --------------------------------------------------------------------------(2)

subtract equation (2) from equation (1)

(By doing that the y variable will be eliminated)

4x = 8

Divide both-side of the equation by 4

4x/4 = 8/4

x = 2

Substitute x =2 into equation (2) and then solve for y

8x−15y=6

8(2)−15y=6

16 - 15y = 6

subtract 16 from both-side of the equation

16 - 16- 15y = 6-16

-15y = -10

Divide both-side of the equation by -15

-15y/-15 = -10/-15

y = $\frac{2}{3}$

x = 2 and y = $\frac{2}{3}$

3 0

3 years ago

Find the gcf 21 28 140

marshall27 [118]

The greatest common factor is 7.

5 0

3 years ago

Read 2 more answers

Explain why sine ratio has a macimum value of 1??

Goshia [24]

Answer:

The maximum length of the opposite side of a right triangle equals the length of the hypotenuse.

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

How do I find the mistake the student did?

Maslowich

Answer:

Step-by-step explanation:

What he did at the end of the given equations is solve for x in x + 8y= 21

x = 21 - 8y Substitute that result in the top equation.

7(21 - 8y) + 5y = 14 is the correct step To continue Remove the brackets

147 - 56y + 5y = 14 Combine

147 - 51y = 14 Add 51y to both sides.

147 = 51y + 14 Subtract 14 from both sides.

133 = 51y divide by 51

y = 2.61 rounded.

The incorrect step is underlined and italicized.

4 0

3 years ago

Five years ago, Nina was twice as old as Sam. In five years, she will be 1.5 times as old as Sam. How old are Nina and Sam now?

Margarita [4]

Answer:

age of Sam= 15 years

age of Nina = 25 years

Step-by-step explanation:

Let Nina's age be X years

Let Sam's age be Y years

Five years ago Nina's age will be X- 5 years

Five years ago Sam's age will be Y- 5 years

Given in question

Five years ago, Nina was twice as old as Sam

writing it mathematically using X and Y we have

Nina's age = 2 * Sam's age

X- 5 = 2 *(Y- 5)

X = 2 *(Y- 5) + 5 = 2Y - 10 + 5 = 2Y - 5 _________________equation A

__________________________________________________________

Five years in future Nina's age will be X+ 5 years

Five years ago Sam's age will be Y+ 5 years

Given in question

In five years, she will be 1.5 times as old as Sam

writing it mathematically using X and Y we have

Nina's age = 1.5 * Sam's age

X+5 = 1.5 *(Y+ 5)

X = 1.5*(Y+5) -5 = 1.5Y +7.5 - 5 = 1.5Y +2.5 _________________equation B

_______________________________________

in equation A we have X = 2Y - 5

in equation B we have X = 1.5Y + 2.5

equating equation A and B we have

2Y - 5 = 1.5Y +2.5

=> 2Y - 1.5Y = 2.5 + 5

=> 0.5Y = 7.5

=> Y = 7.5/0.5 = 15

from equation A we have

X = 2Y - 5 (substituting the value of Y = 15 in equation we have)

X = 2*15 - 5 = 25

Therefore age of Sam= 15 years

age of Nina = 25 years

4 0

3 years ago