All categories

4 years ago

Solve the system 5x+3y=-9 &- 2x+y=8

Mathematics

2 answers:

kiruha [24]4 years ago

6 0

I got the same answer as you which is
X=(-3)
Y=(2)

lianna [129]4 years ago

3 0

5x+3y=-9
-2x+y=8

The first step is the trickery (and quite frankly, hardest to explain) part. You need to multiply one equation by a number that will create one variable to be the negative version of the other...(Confusing, right? Don't worry, I'll show you)

We are going to solve for X first.

We will multiply the second equation by -3
5x+3y=-9
-3(-2x+y)=(-3)8

Now simplify:
5x+3y= -9
6x-3y= -24

Now combine the two equations (add them together)
11x= -33
Divide by 11
X=-3

Now plug X in to one of the first equations:
5(-3)+3y= -9
-15+3y =-9
3Y= 6
Y= 2

So your final answer is:
x= -3
Y= 2

Hope this helps!

You might be interested in

Solve the proportion. 3/6 = 7/d

AysviL [449]

To solve this proportion:

$\frac{3}{6} =\frac{7}{d}$

Simplify 3/6, it reduces to 1/2

$\frac{1}{2} =\frac{7}{d}$

Then do the Criss cross method

1d = 7 ×2

d=14

Hope it helps!

6 0

2 years ago

Read 2 more answers

Wich expression represent the sum of 59 and x

KIM [24]

I don't see the answers, but it would most likely be 59 + x.

7 0

4 years ago

The ratio of dogs to cats at a local animal shelter is 13/25. Which statement must be true?

Ivan

Option:

a. for every 13 dogs, there are 25 cats.

b. there are twice as many cats as dogs at the shelter.

c. the shelter has more dogs than cats.

d. there are 25 animals in the shelter.

Answer:

a. for every 13 dogs, there are 25 cats.

Step-by-step explanation:

Represent Dogs with D and Cats with C;

So;

$\frac{D}{C} = \frac{13}{25}$

By comparison:

$D=13$

$C = 25$

This implies that:

For every 13 D, there are 25 C

Hence: Option A is true

6 0

3 years ago

Marat540 [252]

Answer:

Plan A equation: y = 10x + 30

Plan B equation: y = x + 80

Plan C equation: y = 5x + 50

Plan A costs the same as Plan C in 4 months

Plan A is the better option if you use 0 - 4 GBs of data each month

Plan B becomes the better deal when 8 months pass

Step-by-step explanation:

When does Plan A cost the same as Plan C?

Set the equations equal to each other (the cost) and solve for x (time in months)

10x + 30 = 5x + 50

5x = 20

x = 4 months

Which plan is best if you only use 0-4 GBs of data a month?

Test the maximum and minimum values to check which plan costs less

At 0 GBs of data used per month

Plan A: y = 0 + $ 30 = $30 total

Plan B: y = 0 +$80 = $80 total

Plan C: y = 0 + $50 = $50 total

At 4 GBs of data used per month

Plan A: y = $ 40 + $ 30 = $ 70

Plan B: y = $ 4 + $ 80 = $ 84

Plan C: y = $ 20 + $ 50 = $ 70

Comparing the plans at maximum and minimum amount of GBs used, only one plan has the lowest cost overall. Even though Plan C is the same price at 4 GBs as Plan A, when you use 0 GBs you will end up paying more in Plan C than Plan A. Therefore, Plan A is the better option

When does Plan B become the best deal?

When you plot the different Plans on a graph, the slope intercept of x = 7.5 (rounded up to 8) yields the lowest cost for plan B

5 0

3 years ago

Perform the following operation, and report the answer to the correct number of significant figures. 3.47 x 6.7

kobusy [5.1K]

Answer:

Step-by-step explanation:

3.47 = 3 sig. figs.

6.7 = 2 sig. figs.

Since these two numbers are being multiplied, you would round to the smallest number of sig. figs. of the two. In this case, it would be 2 significant figures.

3.47 * 6.7 = 23.249 (dont forget to round to 2 sig. figs. ) --> 23

6 0

3 years ago