Question

solve the system of equations by the elimination method: 11x-8y=92 9x+5y=6
why do you multiplythe first equation by5 and the second by 8

Answer 1

11x - 8y = 92 (1)

9x + 5y = 6 (2)


multiply equation (1) by 5 to get:

55x - 40y = 460 (3)

multiply equation (2) by 8 to get:

72x + 40y = 48 (4)

now add (3) and (4) to get

127x = 508

now divide by 127 to get

x = 508/127 = 4

now use this value of x in eq (1) to find y






in summary, we multiply the equations until we can add them together or take them away to eliminate a variable (in this case we did y)

then we solve for the remaining variable (x = 4)

and use this to solve for y