This week in Pre Calc 11,

We learned how to solve systems of equations using substitution.

A way to solve a linear system or quadratic system or both is to use the substitution method.

We do this by substituting a y-value in an equation with the other. to start you first substitute y in the second equation with the first equation (since y = y). Because it is harder to solve an equation if it has two variables. After substituting y into the equation and solving for x, the value of x can then be used to find y by substituting the number you found, with x. While using the substitution method, you can also start by substituting x in the second equation with the first equation. You can start of by substituting x first or y your choice.
For example :
y = 2x + 2
y = x^2 + 5x +4
Take the first equation and replace it with the y in the second.
2x + 2 = x^2 + 5x +4
Solve for x.

0= x^2+3x+2

0= (x+3)(x+1)