Question

solve for x and y using elimination method 7x-2y =9, 4x +6y = -2​

Answer 1

Answer:

$y=-1$ ; $x=1$

Step-by-step explanation:

Elimination method for (i) and (ii)

7x    -2y =   9--------------------------(i)

4x   +6y=  -2---------------------------(ii)

(-)    (-)      (+)

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

3x-8y   =11

3x=11+8y

$x=\frac{11+8y}{3}$ --------------------------------(iii)

substitute (iii) in (ii)

$4(\frac{11+8y}{3} )+6y=-2$

$\frac{44+32y}{3}+6y=-2$

$\frac{44+32y}{3} +\frac{18y}{3} =-2$

$\frac{44+32y+18y}{3}=-2$

$44+32y+18y=-6$

$50y=-50$

$y=-\frac{50}{50}$

$y=-1$  ---------------------------------(iv)

substituting (iv) in (i)

$7x-2(-1)=9$

$7x+2=9$

$7x=9-2$

$7x=7$

$x=\frac{7}{7}$

$x=1$ ----------------------------------(v)

equation (iv) and (v) are the answers

$y=-1$ ; $x=1$