How many solutions does the following system of equations have? y=5/2x+2 and 2y=5x+8

Mathematics · Middle School · Tue Nov 03 2020

Answered on

We have,

y=5/2x+2 and 2y=5x+8

Now, y = 5/2x + 2

y = (5x + 4)/2

2y = 5x + 4

5x - 2y + 4 = 0     ….1 

And ,2y = 5x + 8 

So, 5x - 2y + 8 = 0     …2

a1 = 5 , b1 = -2 , c1 = 4

a2 = 5, b2 = -2 , c2 = 8

So, a1/a2 = 5/5 = 1

b1/b2 = -2/-2 = 1

And, c1/c2 = 4/8 = 1/ 2

So, a1/a2 = b1/b2 ≠ c1/c2

That means given equations have no solutions

Answered on

For finding how many solution can have a system of equations we do 

a(2)/a(3)=b(1)/b(2)=c(1)/c(2)….(1)

Form the Given equations 

y=5/2x+2  where a(1)= 5/2,b(1)= 2

and 2y=5x+8 , simplify y=5x/2+4 ,where a(2)= 5/2,b(2)= 4

By equation (1) 

(5/2)/(5/2)=2/4

1=½

So for the given equations  a(2)/a(3)=b(1)/b(2)=c(1)/c(2) not equal This means that there are no values of x such that these two lines are equal, hence they are parallel and there are no solutions.