Question

What is the solution of y − 4x = 0 and 3x + 6y = 9?

Answer 1

do you prefer substitution or elimination

Answer 2

substitution a) x=0, y=3/2 b) x=1/3, y=4/3 c) x=1 y=-1 d) x=1/4, y=2/3

Answer 3

y - 4x = 0
y = 4x
now sub 4x in for y in the other equation
3x + 6y = 9
3x + 6(4x) = 9
3x + 24x = 9
27x = 9
x = 9/27
x = 1/3
now sub 1/3 in for x in either equation to find y
y = 4x
y = 4(1/3)
y = 4/3

any questions ?