Welcome :: Homework Help and Answers :: Mathskey.com

Recent Visits

    
Welcome to Mathskey.com Question & Answers Community. Ask any math/science homework question and receive answers from other members of the community.

13,260 questions

17,801 answers

1,438 comments

33,888 users

3x+4y=15 and 2x-4y=30 Solving systems of Equations using Substitution and elimination

0 votes

Some Algebra 1 ive need some help on.

asked Dec 2, 2013 in ALGEBRA 1 by payton Apprentice

1 Answer

0 votes

Elimination method

3x+4y = 15 -----> (1)

2x-4y = 30 --------> (2)

To eliminate the y value add the equations (1) and(2).

3x+4y = 15

2x-4y = 30

_________

5x = 45

Divide to each side by 5.

5x/5 = 45/5

x = 9

Substitute the x value in (1).

3*9+4y = 15

27+4y = 15

Subtract 27 from each side.

27-27+4y = 15-27

4y = -12

Divide to each side by 4.

4y/4 = -12/4

y = - 3

Solution is x =9, y = -3.

answered Dec 2, 2013 by william Mentor

Related questions

...