Question

100 POINTS!!!! PLEASE HELP ASAP!!! EXPLANATION WOULD BE GREATLY APPRECIATED!

No one answered my other post and I really need help and fast! So I answered a bunch of questions and gained some more points. Hopefully this is amount is enough incentive for people to help. It’s the most points I can put up.

Choose the best method for solving each system.

1.) x+3y=7
5x+11y=3

A. Graphing
B. Substitution
C. Elimination

2.) 5x-3y=3
2x+7y=6

A. Graphing
B. Substitution
C. Elimination

3.) Sally is comparing the costs of two dressmakers for her bridesmaids’ dresses. Given the differing costs per dress and consultation fee for two different seamstresses, compare the two choices and decide which seamstress would be the better choice according to how she increases or decreases her wedding party.

A. Graphing
B. Substitution
C. Elimination

Answer 1

1) B- Substitution

2) C- Elimination

3) A- Graphing

Explanation:

1)

x+3y=7

5x+11y=3

x = 7 - 3y

Plug this x into the second equation and solve for y first

2)

5x-3y=3 --> (1)

2x+7y=6 --> (2)

Since making any variable the subject would involve fractions, it's better to go for elimination

7(1) + 3(2)

would eliminate y

3)

While comparing cost and adjusting choices, a graph is a better approach because all the possibilities are right in front