ANSWER and EXPLANATION
We are given the two equations:
4x + 5y = 15
and
8x + 4y = 4
To rewrite it in the slope-intercept form, we have to write them in the form:
y = mx + c
where m = slope
c = y intercept
Therefore, we have that 4x + 5y = 15 becomes:
4x + 5y = 15
=> 5y = - 4x + 15
Divide through by 5:
y = (-4/5)x + 15/5
y = -0.8x + 3
8x + 4y = 4 becomes:
8x + 4y = 4
=> 4y = -8x + 4
Divide through by 4:
y = (-8/4)x + 4/4
y = -2x + 1
For two lines to be parallel, their slopes (m) must be equal.
From the two equations given, the slopes are not equal, so they are not parallel.