Respuesta :

Answer:

7x + 5(-10x - 9) = -217

7x - 50x - 45 = -217

-43x - 45 = -217

-43x = -172

x = 4

y = -10(4) - 9

y= -40 - 9

y= -49

(4, -49)

Answer:

[tex]x=4,\:y=-49[/tex]

Step-by-step explanation:

we are given with two linear equations and asked to solve them for x and y .

We will solve them by substitution method.

Given that

[tex]y=-10x-9[/tex]

We replace this value of y in second equation that is

[tex]7x+5y=-217[/tex]

[tex]\mathrm{Subsititute\:}y=-10x-9[/tex]

[tex]7x+5\left(-10x-9\right)=-217[/tex]

[tex]7x-50x-45=-217[/tex]

[tex]\mathrm{Add\:similar\:elements:}\:7x-50x=-43x[/tex]

[tex]-43x-45=-217[/tex]

[tex]\mathrm{Add\:}45\mathrm{\:to\:both\:sides}[/tex]

[tex]-43x=-172[/tex]

[tex]\mathrm{Divide\:both\:sides\:by\:}-43[/tex]

[tex]x=4[/tex]

[tex]\mathrm{For\:}y=-10x-9[/tex]

[tex]\mathrm{Subsititute\:}x=4[/tex]

[tex]y=-10\cdot \:4-9[/tex]

[tex]y=-49[/tex]

[tex]\mathrm{The\:solutions\:to\:the\:system\:of\:equations\:are:}[/tex]

[tex]x=4,\:y=-49[/tex]