Question

if 4x+6y=15xy and 3x-4y=7xy, then 8x-3y is equal to​

Answer 1

Answer:

15

Step-by-step explanation:

2 * 4x+6y=15xy

3 * 3x-4y=7xy

so 8x+12y=30xy

9x-12y=21xy

-------------------

17x =51xy

1=3y

y=1/3

sub value of y we can get x as 2

8x-3y = 8(2)-3(1/3)

=16-1

ANS=15

Answer 2

SOLUTION

GIVEN

4x + 6y = 15xy and 3x - 4y = 7xy

TO DETERMINE

The value of 8x - 3y

EVALUATION

Here the given system of equations are

4x + 6y = 15xy - - - - - - (1)

3x - 4y = 7xy - - - - - - - (2)

Multiplying both sides of Equation 1 by 3 we get

12x + 18y = 45xy - - - - - (3)

Multiplying both sides of Equation 2 by 4 we get

12x - 16y = 28xy - - - - - (4)

Equation 3 - Equation 4 gives

34y = 17xy

⇒ 17xy = 34y

⇒ 17x = 34

⇒ x = 2

From Equation 1 we get

4x + 6y = 15xy

$\displaystyle \sf{ \implies 8 + 6y = 30y}$

$\displaystyle \sf{ \implies 24y = 8}$

$\displaystyle \sf{ \implies y = \frac{8}{24} }$

$\displaystyle \sf{ \implies y = \frac{1}{3} }$

Now we have

$\displaystyle \sf{ 8x - 3y}$

$\displaystyle \sf{ = (8 \times 2) - (3 \times \frac{1}{3} )}$

$\displaystyle \sf{ = 16 - 1}$

$\displaystyle \sf{ =15}$

━━━━━━━━━━━━━━━━

Learn more from Brainly :-

$1.$ Solve the given system of equations.

2x + 8y = 5 24x - 4y = -15

https://brainly.in/question/33685046

2. 2x+3y=12 and 4x+5y=22

https://brainly.in/question/18427922