Question

How many solutions does the following system have?
y = -2/3 x + 3 and 2x + 3y = 9

Answer 1

I need an answer, even with previous help I'm unable to solve it.

Answer 2

can you solve for "y" on the 2nd equation?

Answer 3

How would I?

Answer 4

I'm so terrible at math, all my grades are B+'s and above except math. Its such a struggle for me.

Answer 5

well.. do you know how to isolate a variable on one side?

Answer 6

Nope ._.

Answer 7

well... http://www.youtube.com/watch?v=ldYGiXSHa_Q <---- is how you'd solve for a variable or "isolate it" so-called, and thus you can do that on the 2nd equation

once you have both equations solved for "y", check them both

Answer 8

Solve the second equation for y. If you compare the the RHS of each other you will discover that they are the equation for the same line. A plot is attached.

Answer 9

I'm still unable to solve it. I need an answer. :/

Answer 10

To find out the number of solutions ........ solve the 2nd equation and set linear lines equal and solve again.

Y = - 2/3x + 3 is good. (Its in the form of Y=Mx + b

Now ... -2x + 3y = 9 needs to be in the form of Y = Mx + b

2x + 3y = 9

When you get it in Y=Mx + b you will get:

3y = -2x + 9

Divide both sides by 3 (getting Y by itself.)

Y = -2/3x + 3

Set your linear points equal:

y = -2/3x + 3 = -2/3x + 9

Combine like terms:

-2/3x + 2/3x = 9 - 3

Solve

0 = 3

0 = 3 < Since zero CLEARLY does not equal 3, your lines don't intersect at a single point. Next case...

Both lines are the SAME line over lapping each other. (That means INFINITE solutions are possible)