All categories

3 years ago

4x + 5y = 7 and 8x + 5y = 9 * Elimination

Mathematics

2 answers:

Luden [163]3 years ago

7 0

Answer:

Solve equation [2] for the variable y

[2] y = 8x + 7

// Plug this in for variable y in equation [1]

[1] 4x - 5•(8x+7) = -9

[1] -36x = 26

// Solve equation [1] for the variable x

[1] 36x = - 26

[1] x = - 13/18

// By now we know this much :

x = -13/18

y = 8x+7

// Use the x value to solve for y

y = 8(-13/18)+7 = 11/9

Solution :

{x,y} = {-13/18,11/9}

bazaltina [42]3 years ago

4 0

It should be y=2 after you eliminate

You might be interested in

Find the inverse Laplace transform f(t) of the function F(s). Write uc for the Heaviside function that turns on at c, not uc(t).

zzz [600]

Answer:

F(t) $=\frac{-1}{2}e^{7(t-7)}+\frac{1}{2}e^{-7(t-7)}$

Step-by-step explanation:

We have given $F(S)=\frac{7e^{-7s}}{s^2-49}$

Now $F(S)=e^{-7s}G(s)$

Here $G(S)=\frac{7}{S^2-49}$

Now first find the Laplace inverse of G(S)

Using partial fraction

$\frac{7}{(s+7)(s-7)}=\frac{A}{(S+7)}+\frac{B}{S-7}$

$7=A(S-7)+B(S+7)$

On comparing the coefficient

$A=\frac{1}{2}$ and $B=\frac{-1}{2}$

On putting the value of A and B

$G(S)=\frac{-1}{2(S+7)}+\frac{1}{2(S+7)}$

Taking inverse Laplace

$G(t)=\frac{-1}{2}e^{7t}+\frac{1}{2}e^{-7t}$

Now in G(s) there is onether term $e^{-7s}$

So F(t) $=\frac{-1}{2}e^{7(t-7)}+\frac{1}{2}e^{-7(t-7)}$

6 0

3 years ago

A bag contains 8 blue marbles, 7 green marbles, and 5 red marbles.

Alina [70]

the probability is 5 out of 20

3 0

3 years ago

Subtract 5 from 1/3 of 23

WARRIOR [948]

The answer is 2.8. or around there

5 0

3 years ago

Read 2 more answers

I need helpppp:( like im failing this class

Olin [163]

Answer:

dont even stress i gotchu

It's 50*, 46* and 84*.

Ratio of the second problem is 1:1 they both have a slope of 1 (which is probably why all three points are on the same line)

Step-by-step explanation:

Since we know that the straight/flat angle would equal 180* we will set the total of all those angles to 180*

We will add them up to find x. Once we find x we can find the value of each angle.

6x-10 + 4x + 6 + 7x + 14 = 180

We will combine like terms and solve for x.

17x+10 = 180

17x = 170

x = 10.

Since we have x = 10, we will plug it into x of each angle to get the value of each angle.

6(10) -10 = 60-10 which equals 50*

4(10) + 6 = 40+6 which equals 46*

7(10) + 14 = 70 + 14 which equals 84*.

8 0

3 years ago

Evaluate the series 4 – 2 + 1 – 0.5 + 0.25 to S10. Round to the nearest hundredth.

aleksklad [387]

The initial term of this geometric series is 4, and the common ratio is -1/2. The sum is given by

$S_{n}=a_{1}\dfrac{r^{n}-1}{r-1}\\\\S_{10}=4\cdot \dfrac{(-\frac{1}{2})^{10}-1}{-\frac{1}{2}-1}=4\cdot \dfrac{(\frac{1}{1024}-1)}{(-\frac{3}{2})}\\\\=\dfrac{8}{3}\cdot \dfrac{1023}{1024}=\dfrac{341}{128}$

The sum is approximately 2.66.

4 0

3 years ago