Question

Solve the following system of equations by the substitution method.
10x + 10y = 1
x = y - 3
What is the value of y?
-29/20
31/20
-3/2

Answer 1

Replace x by its value in the first equation to get
10(y-3)+ 10 y =1
Solve this equation for y

Answer 2

31/20

Answer 3

Now find x.
x= y-3

Answer 4

10x + 10y = 1
you substitute, ill come out like this
10(y - 3) + 10y = 1
10y - 30 + 10y = 1
10y + 10y = 1 + 30
20y = 31
y = 31/20
All it is is simplifying and arranging it to isolate y, since that is what your looking for.

Answer 5

-29/20

Answer 6

x= 31/20 -3=-29/20