Question

Solve the following system of equations by the elimination method.
1/3x+1/4y=7
1/3x-3/4y=-9

a)The solution is___?(Type an ordered pair. Use integers or fractions for any numbers in the expression)

b)Infinitely many solutions

c)No solution

Answer 1

1/3x + 1/4y = 7
1/3x - 3/4y = -9

Make one of the equations negative to eliminate the x's.

-(1/3x + 1/4y) = -(7)

-1/3x - 1/4y = -7
1/3x - 3/4y = -9
____________________
-y = -16
y = 16

Now solve for x. Use either equation.

1/3x + 1/4(16) = 7
1/3x + 4 = 7

Eliminate the fraction by multiplying the equation by three.

3(1/3x + 4) = 3(7)
x + 12 = 21
x = 21 - 12
x = 9

Solution:
(9, 16)

Answer 2

thank you