Thread: Substitution

Could someone help me with this one?

Use substitution to solve the system | y=2-x/2
| x[squared]+4y=8

Originally Posted by gretchen

Could someone help me with this one?

Use substitution to solve the system | y=2-x/2
| x[squared]+4y=8

y = 2 - (x/2)

x^2 + 4y = 8

We'll substitute y;

x^2 + 4(2 - (x/2)) = 8

x^2 + 8 - 2x = 8

x^2 - 2x = 0

x*(x - 2) = 0

x = 0 V x = 2

CHECK:

y = 2 - (x/2)

x^2 + 4y = 8

----------------

y = 2 - (0/2)

y = 2

And y = 2 - (2/2)

y = 1

0^2 + 4(2) = 8 ?

Yes;

2^2 + 4(1) = 8 ?

Yes.