Question

3x-8y=-7 and -5x-6y=3. solve saimultanus equation ​

Answer 1

Step-by-step explanation:

by using substitution method...

we have

3x-8y=-7 --------(equation-1)

3x=-7+8y

X=-7+8y/3

and

-5x-6y=3 ----------(equation-2)

now putting the value of 'x' in equation..

we have...

-5(-7+8y/3) - 6y = 3

35-40y/3 - 6y = 3

Answer 2

Answer:

Given Equations:

1. 3x - 8y = -7
2. - 5x - 6y = 3

To solve for x and y, we must eliminate one of the variables, to do so, we have to make the coefficient of that variable same in both equations. So, let's multiply 1st equation by 5 and 2nd equation by 3, so that we have 15 as the coefficient for x in both equations.

Now, multiplying eq.1 by 5 and eq. 2 by 3 and then adding both the equations,

5 (3x - 8y) = 5 × -7

15x - 40y = -35 (eq.3)

And, 3 ( -5x -6y) = 3 × 3

- 15x - 18y = 9 (eq.4)

Adding eqs. 4 & 5,

(15x - 40y) + ( -15x - 18y) = -35 + 9

15x - 15x - 40y - 18y = - 26

- 58 y = -26

y = -26/-58 = 13/29

Now, Substituting the value of y so obtained into 1st equation, (we can substitute it into any of our equations),

3x - 8(13/29) = -7

3x - 104/29 = - 7

3x = - 7 + 104/29

3x = (-203 + 104)/29 (Taking Lcm)

3x = -99/29

x = -99/29 × 3 = - 99/87 = -33/29

Hence the values of x and y obtained from the given set of equations are:

x = -33/29 and y = 13/29