Question 81495
QUESTION:


Solve each of the following systems by substitution.

5x - 2y = -5
y - 5x = 3



ANSWER:



5x - 2y = -5  ------------(1)


y - 5x = 3 ---------------(2)


Add 5x to both sides of the equation (2)



==> y - 5x + 5x = 3 + 5x



==> y = 3 + 5x --------------(3)



Substitute this value of y, that is y = 3 + 5x in equation(1)



==>  5x - 2(3 + 5x) = -5



==> 5x - 2*3 - 2*5x = -5



==> 5x - 6 - 10x = -5



==> 5x - 10x - 6 = -5


==> -5x - 6 = -5


Add 6 to both sides of the equation....


==> -5x - 6 + 6 = -5 + 6



==> -5x = 1



Divide both sides by -5



==> -5x/-5 = 1/-5




==> x = -1/5



Now put the value of x in (3)



==> y = 3 + 5(-1/5)



==> y = 3 + (-1)



==> y = 2




So we have ,


x = -1/5  and 

y = 2




To check your answer, substitute these values in the first equation then you will find it satisfies  the equation.



Hope you found the explanation useful...


Regards.

Praseena.