How do use u substitution?

In the form of algebra substitution is the method used in simultaneous equations.

E. g y=2x+5 and y=5x-1

Solve for x and y

Since we know two examples of what y is, we can substitute one y in replacement of the other to get.

2x+5=5x-1 then we solve for x to get:

x = 2 sub this back in to get y = 2 (2) + 5

y = 9

The substitution method is used to find the values. Simply replace the equations into another, and solve for the 2 values.