Homework Help

If the solution of ax + 3y = 8 and 2x + by = 10 is (3, 4) what are a and b.

user profile pic

lxsptter | Student, Undergraduate | (Level 2) Valedictorian

Posted March 23, 2013 at 5:53 PM via web

dislike 1 like

If the solution of ax + 3y = 8 and 2x + by = 10 is (3, 4) what are a and b.

1 Answer | Add Yours

user profile pic

justaguide | College Teacher | (Level 2) Distinguished Educator

Posted March 23, 2013 at 5:59 PM (Answer #1)

dislike 1 like

The solution of the system of linear equations ax + 3y = 8 and 2x + by = 10 is (3, 4). An easy way to determine the values of a and b is to use the fact that as the two lines intersect at (3, 4) this point lies on both the lines.

Substitute x = 3 and y = 4 in ax + 3y = 8

=> 3a + 12 = 8

=> 3a = -4

=> a = -4/3

Substitute x = 3 and y = 4 in 2x + by = 10

=> 6 + 4b = 10

=> 4b = 4

=> b = 1

The required values of a and b are -4/3 and 1 respectively

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes