Question

What is the y-intercept of the graph of the given line by the equation 3y+4x=15?

A: 5
B: 4
C: 3
D: -4/3

Answer 1

In y-intercept: $x=0$. Hence:

$3y+4\cdot0=15\iff 3y=15\iff \boxed{y=5}$

The intersection is the point $P(0,5)\Longrightarrow \boxed{\boxed{A}}$

Answer 2

To find the y intercept of an equation plug zero in for the x's and solve for y. Remember if it is a y intercept, the x value is zero.
3y + 4(0) = 15 
3y = 15
y = 5  (0,5)