All categories

3 years ago

If 5x-3y=23 and 4x-4y=20, which is the value of x+y?

Mathematics

1 answer:

Readme [11.4K]3 years ago

3 0

Answer:

Step-by-step explanation:

5x-3y=23

4x-4y=20

---------------I'm going to try to set this up for elimination. I notice the bottom equation contains terms that are divisible by 4 so I'm going to divide both sides by 4 on that last equation only...

5x-3y=23

x- y= 5

Now I'm going to multiply the bottom equation by -3 so the y terms will be opposite. When you add opposites you do get 0. That is the whole point of elimination.

5x-3y=23

-3x+3y=-15

------------------ adding

2x+0=8

2x =8

x =4

So using that second equation x-y=5 I will find y given that x=4.

4-y=5

-y =1

y=-1

So the solution to the system is (4,-1)

You are asked to find x+y

So x+y=4+(-1)=3

You might be interested in

What is a 3, 4, 5 triangle?

Alexandra [31]

Answer:

<em>A special right triangle is a right triangle with some regular feature that makes calculations on the triangle easier, or for which simple formulas exist. For example, a right triangle may have angles that form simple relationships, such as 45°–45°–90°. This is called an "angle-based" right triangle.</em>

Step-by-step explanation:

Hope this helps

Have a nice day :)

5 0

3 years ago

Read 2 more answers

PLSS HELP CAN ANYONE HELP ME HURRY

SashulF [63]

The answer is b foo im pretty sure

8 0

4 years ago

Express in simplest a+bi form: Square root of 1b + Square root of -1b

Nimfa-mama [501]

Express in simplest a+bi form: Square root of 1b + Square root of -1b

$\sqrt{1b} + \sqrt{-1b}$

Lets simplify $\sqrt{-b}$

We know $\sqrt{-1} = i$

$\sqrt{-b} =i\sqrt{b)$

We cannot simplify $\sqrt{1b}$

$\sqrt{1b} + \sqrt{-1b}$

$\sqrt{1b} + i\sqrt{b}$

So a + ib form is $\sqrt{1b} + i\sqrt{b}$

5 0

4 years ago

R= I didn’t know it at all so if some one could help me‍♀️ Thank you

alexdok [17]

Answer:

Step-by-step explanation:

3 0

4 years ago

TWO QUESTIONS PLS HELP ASAP

ASHA 777 [7]

Answer: 4. (-1,-1) 3. (3,-2)

4)

Set the equations equal to each other.

4x+3=-x-2

Subtract 3 from both sides

4x=-x-5

Add x to both sides

5x=-5

Divide both sides by 5

x=-1

Next, replace x with -1 in either equation to find y.

-(-1)-2=y

-1=y

3)

Do the same thing for this one and set them equal to each other

-2x+4=-1/3x-1

Add 1 to both sides

-2x+5=-1/3x

Add 2x to both sides

5=5/3x

Divide both sides by 5/3

x=3

Next, replace x with 3 in either equation

-2(3)+4=y

-2=y

4 0

3 years ago