Problem:
Solve by substitution
x=3y
2x+4y = 10
Solution:
let's denote the equation of the problem by:
x=3y EQUATION 1
2x+4y = 10 EQUATION 2
Substitute the x of equation 1 into equation 2:
2(3y) + 4y = 10
this is equivalent to:
6y + 4y = 10
this is equivalent to:
10y = 10
solve for y:
y = 10/10 = 1
then, we can say that y = 1. Now replace this value (y =1) in equation 1:
x = 3y = 3(1) = 3
Thus, we can conclude that the solution is
x= 3 and y = 1
