Respuesta :

Answer:

x = 1

y = 2

Step-by-step explanation:

Solve by substitution

1) Solve for x in 7x + 8y = 23

x = 28 - 8y/7

2) Substitute x = 23-8y/7 into 8x - 4y = 0

8(23-8y)/7 - 4y = 0

3) Solve for y in 8(23-8y)/7 - 4y = 0

y = 2

4) Substitute y = 2 into x = 23-8y/7

x = 1

5) Therefore,

x = 1

y = 2

[tex]7x+8y -23=0 ~~~\\\\8x-4y+0 =0\\\\\text{Using cross multiplication method,}\\\\\\\dfrac{x}{8(0)- (-23)(-4)} = \dfrac{y}{8(-23) -7(0)} = \dfrac 1{7(-4) - (8)(8)}}\\\\\\\implies \dfrac x{0-92} = \dfrac y{-184-0} =\dfrac 1{-28 -64}\\\\\\\implies -\dfrac x{92} = -\dfrac{y}{184} = - \dfrac 1{92}\\\\\\\implies \dfrac{x}{92} = \dfrac y{184} = \dfrac 1{92}\\\\\text{Hence,}\\\\x= \dfrac{92}{92} = 1\\\\y= \dfrac{184}{92} = 2[/tex]