Thursday, December 11, 2008

Back to the Problems...


Now that you've had a couple days graphing systems of linear equations, take another look at the two word problems from our blog problems Tuesday!


For each problem please do /answer the following:
1) Identify variables
2) Write equations for the word problems
3) Solve the system of equations using graphing - remember, you may have to manipulate the linear equation! (You may use your calculator or the online calcualtor to assist you.)
4) Were your original answers correct?
5) Did you find using systems of equations to be useful/helpful? Explain.

22 comments:

Anonymous said...

problem 2

(y,x)
y=-3x+25

y=-.625+8.375
my original answer was correct and using the graphing calculator was much easier.
(7,4)

Anonymous said...

problem 1
(x,y)
y=-x+12
y=x+4
(4,8)
it was much easier

Anonymous said...

1) x,y
2)x+y=12
x+y=4
12-4=8
8+y=12
12-8=4
8+4=12
12-8=4
9x+3y=8x+5y
3)

Anonymous said...

problem 1
x+y=12
x-y=4
put them in slope in slope int. then graph them

Anonymous said...

x,y P1.
x+y=12
x+y=4
12-4=8
p2.Y=-3X+25
Y=.625+8.375
MY ANSWER WAS CORRECT.
(7,4)

Anonymous said...

(x,y)
y=-x+12
y=x+4
(4,8)
yes, my original answer was correct. It was much easier though to do this, because you don't have to just guess and check.There's more of a structure to how you solve the problem.
#1

Anonymous said...

Problem 1:
(x,y)
x+y=12
x+y=4
(4,8)

My answer was correct the first time.
I'd rather solve it the other way and check it with graphing.

Anonymous said...

Problem 2:
(x,y)
3x+9y=75.
8x+5y=67.
Then you get (7,4)

I got the answer correct the first time.
I like the other way better.

Anonymous said...

Problem 1:
1.) x and y
2.) x + y = 12; x - y = 4
3.) Done on calculator
4.) The sum was right, the diff. was wrong
5.) It did because it helped me check my work. I found new answers for the problem: (-4, 8)

Anonymous said...

Problem 2:
1.) x and y
2.) 3x + 9y = 75; 8x + 5x = 67
3.) Done on Online Calculator.
4.) Yes.
5.) Yes because it helped me check my answer.

Anonymous said...

(x,y)
3x+9y=75
8x+5y=67
(7,4)

my orginal answer was right and i like the other way better.
#2

Anonymous said...

Problem #1

Variable:
(x,y)
1st equation: y=-x+12
2nd equation: y=x+4
my intersection point was (4,8)

My answer was correct!!!

This was much easier because you could check it to make sure it was right and graph it to see that your answer is correct

Problem # 2

(x,y)

1st equation: 3x+9y=75
2nd equation: 8x+5y=67

then you get (7,4)

I was correct this one was much harder then the 1st

Anonymous said...

Problem 1:

(x,y)
y=-x+12
y=x+4
(4,8)
Yes my original answer was correct. I now don't have to guess and check but just plug in the answer.

Anonymous said...

Problem 2:

x,y)
3x+9y=75
8x+5y=67
(7,4)

I found it is much easier and more efficient to do it this way.

Anonymous said...

Problem 1
(x,y)
y=-x+12
y=x+4



Problem 2

(y,x)
y=-3x+25

y=-.625+8.375

It was a lot easier with the calculator and i was right

Anonymous said...

Mrs.Nelson I need help.

Anonymous said...

Problem 1 :
(x,y)
y=-x+12
y=x+4
Yes
It was helpful because it helps me check my answers.

Anonymous said...

problem 2:
(c,s)
9c+3s=$75
&
5c+8s=$67
9(7)+3(4)=$75
5(7)+8(4)=$67
Yes
Graphing calculator was easier

Anonymous said...

problem 1
(x,y)
y=-x+12
y=x+4
(4'8)
My frist answer was right and this
way is easier to use but for me it takes more time.

Anonymous said...

problem 2
(x,y)

3x+9x=75

8x+5y=67

At the end you get (7,4)

My first answer was wrong for this because the other half didn't work.So this way gets you a better answer so this way is better.

Anonymous said...

I know it's late but...

1.) (x,y)
2.) x + y = 12
x - y = 4
3.) Work done on calculator.
4.) Yes.
5.) I liked my original way better because it was a little easier to understand.

* Answers: (x=8, y=4)

Anonymous said...

1.)(x,y)
2.) 3x + 9y = 75.
8x + 5y = 67.
3.) Done on calculator.
4.) My original answers were correct.
5.) It was more helpful on this one because I was able to check it with graphing and KNOW that it was correct.