All categories

2 years ago

Solve the system by elimination method 7x+5y=-25 5x+3y=-23

Mathematics

1 answer:

Kisachek [45]2 years ago

7 0

The solution is x = -10, y = 9

Step-by-step explanation:

Given equations are:

$7x+5y = -25\ \ \ \ Eqn\ 1\\5x+3y = -23\ \ \ Eqn\ 2$

Multiplying equation 1 by 3

$3(7x+5y) = -25 * 3\\21x+15y = -75\ \ \ Eqn\ 3$

Multiplying equation 2 by 5

$5(5x+3y) = -23 * 5\\25x+15y = -115\ \ \ Eqn\ 2$

Subtracting equation 3 from equation 4

$(25x+15y) - (21x+15y) = -115 - (-75)\\25x+15y-21x-15y = -115+75\\4x = -40$

Dividing both sides by 4

$\frac{4x}{4} = \frac{-40}{4}\\x = -10$

Putting x = -1 in equation 1

$7(-10)+5y = -25\\-70+5y = -25\\5y = -25+70\\5y = 45$

Dividing both sides by 5

$\frac{5y}{5} = \frac{45}{5}\\y = 9$

Hence,

The solution is x = -10, y = 9

Keywords: Linear equations, variables

Learn more about linear equations at:

#LearnwithBrainly

You might be interested in

Please help math !!!!!!

Andrews [41]

I think it’s the second choice

3 0

3 years ago

Read 2 more answers

10. The sum of two numbers is 6 less than twice the first number. Their difference is 10 less than four times the second number.

Ilya [14]

Answer:

10 and 4.

Step-by-step explanation:

Let x be the first number.

Let y be the second number.

x + y = 2x - 6

x - y = 4y - 10

x = 4y - 10 + y

x = 5y - 10

(5y - 10) + y = 2(5y - 10) - 6

6y - 10 = 10y - 20 - 6

6y - 10 = 10y - 26

6y - 10y = -26 + 10

-4y = -16

y = 4

x - (4) = 4(4) - 10

x - 4 = 16 - 10

x - 4 = 6

x = 6 + 4

x = 10

3 0

3 years ago

How many solutions are there to the equation below? 12x + 32 = 12x - 7

marshall27 [118]

0 solutions

move the x to one side, and the numbers to the other.

12x (-12x) + 32 (-32)= 12 (-12x) - 7 (-32)

12x - 12x = -7 - 32

0 = -39

0 ≠ -39

∴ you have 0 solutions

hope this helps

4 0

3 years ago

Read 2 more answers

A manufacture inspects 800 light bulbs and finds that 796 of them have no defects. What is the experimental probability that a l

BartSMP [9]

Answer:

The experimental probability that a light build chosen at random has no defects is 99.5 % or P(A)=0.995.

Step-by-step explanation:

let S be the sample space for the inspection of the light bulbs.

Therefore, n(s) = 800

let ' A ' be the event of no defects bulbs.

Therefore, n(A) = 796

Now the Experiment probability for a light bulb chosen has no defects will be given by,

$P(A)=\dfrac{n(A)}{n(S)}$

Substituting the values we get

$P(A)=\dfrac{796}{800}=0.995$

The experimental probability that a light build chosen at random has no defects is 99.5 % or P(A)=0.995.

3 0

3 years ago

PLEASE HELP!! I WILL GIVE BRAINLIEST AND POINTS!!

Bingel [31]

Answer:

Rewrite in vertex form and use this form to find the vertex

(h,k).(−3,9)

Step-by-step explanation:

3 0

2 years ago