Question

The y-intercept of the line 3x+y+1=0 is: a) -1/3 , b)1/3 ,c)-1 , d)1​

Answer 1

The y-intercept is -1

c)-1

Explanation:

Given:

1. The equation of a line is 3x+y+1=0

To find:

The y-intercept

Formula:

y = mx+c

Solution:

Method 1:

==> 3x+y+1 =0

==> Convert this equation into y=mx+c format

==> 3x+y = -1

==> y = -3x-1

==> Slope m = -3

==> y-intercept = -1

Method 2:

==> We know that,

==> to find x-intercept y=0

==> y-intercept , x=0

==> apply the value x in the equation

==> 3x+y=-1

==> y=mx+c

==> y=-3x-1

==> x=0

==> y = -3(0)-1

==> y = 0-1

==> y = -1

The y-intercept is -1

c)-1