Question

4. What is the value of Dx for the
simultaneous equation 3x + 2y + 11 = 0
and 7x - 4y = 9?"​

Answer 1

Answer:

Step-by-step explanation:

$3x + 2y + 11 = 0$ ------------- (i)

$7x - 4y = 9$ ------------- (ii)

In Equation (i)

$3x + 2y = -11$

∴ $2y = -11 -3x$

∴ $y = \frac{-11 -3x}{2}$

Putting the value of y in Equation (ii), we get

$7x - 4(\frac{-11 -3x}{2}) = 9$

∴ $7x - 2({-11 -3x}) = 9$

∴ $7x + 22 + 6x = 9$

∴ $13x + 22 = 9$

∴ $x = \frac{9 - 22}{13}$

∴ $x = \frac{-13}{13}$

∴ $x = -1$

Thus, value of x is -1. Putting value of x in equation (ii), we get

$7(-1) - 4y = 9$

∴ $-7 -4y = 9$

∴ $-4y = 9+7$

∴ $y = \frac{16}{-4}$

∴ $y = -4$

Answer 2

Answer:

-62

hope its helpfull