Question

Solve each system of equations using the method of your choice: Substitution, Elimination, or Graphing.

y = x + 1
2x + y = 10
Select one:
(1, 5)
(3, 4)
(2, 4)
(4, 2)

Solve each system of equations using the method of your choice: Substitution, Elimination, or Graphing.

3x + 5y = 2
x + 4y = -4
Select one:
(3, 3)
(4, -2)
(2, 4)
(0, 4)

Tricia has $15 and she earns $6 an hour walking dogs. Mike has $9 and he earns $8 an hour walking dogs. Use the system of linear equations to find the number of hours of work after which Tricia and Mike will have the same amount of money.

Answer 1

y = x + 1
2x + y = 10

with this problem, I'd use substitution. Substitute the 1st equation into the second. You'll have:
2x+(x+1)=10 Now solve for x

Answer 2

hm?

Answer 3

I am a little confused on this one

Answer 4

I'm doing it on paper now.

Answer 5

I substituted in x+1 where I saw a y in the second problem.
2x+(x+1)=10

Answer 6

When I simplify (add like terms) I get 3x+1=10

Answer 7

Well I did it and what I got wasn't in one of my options..

Answer 8

3x+1=10
3x+1-1=10-1
3x=9
x=3

Answer 9

Yes thats what I did

Answer 10

(1, 5)
(3, 4)
(2, 4)
(4, 2)

Answer 11

I gotta choose out of those

Answer 12

OK, to get y, substitute back into the original equations
3+1=y
4=y

(3,4)

Answer 13

second choice

Answer 14

Ok

Answer 15

3x + 5y = 2
x + 4y = -4

You can solve this by substitution if you solve the 2nd equation for x...then solve for y...or you could use elimination. Since I've done a substitution problem, let's use elimination. I'm going to eliminate the x's.

Answer 16

Ok

Answer 17

3x + 5y = 2 3x + 5y = 2 3x+5y=2
x + 4y = -4 -3(x +4y=-4) -3x-12y=12
---------
-7y=14
y=-2

Now solve for x

Answer 18

OK one second

Answer 19

Ok i got (4,-2)

Answer 20

Right...great!

Answer 21

Yay!

Answer 22

Tricia has $15 and she earns $6 an hour walking dogs. Mike has $9 and he earns $8 an hour walking dogs. Use the system of linear equations to find the number of hours of work after which Tricia and Mike will have the same amount of money.

m = 6h + 15
m = 8h + 9
Select one:
7 hours
5 hours
1 hour
3 hours

Answer 23

Could you help me with that one?

Answer 24

sure...since both equations are m=something, I'd put each equation equal to each other. 6h+15=8h+9 solve for h

Answer 25

I'm doing it

Answer 26

I sub. 9 from both sides as step one and now I have 6h + 6 = 8h?

Answer 27

then I subtracted 6h from each side and I got 6 = 2h and divided two from each side and got 3=h

Answer 28

yes...so after 3 hours, they're making the same amount of money

Answer 29

good job

Answer 30

Ok :) Thank you

Answer 31

Have a great day!

Answer 32

You too