Question

what is the y intercept of a line with a slope of 2 and containing the point (3,4)

Answer 1

The line cross the Y axis in y=-2

The equation of a line is Y=ax+b where a is the slope and b the y intercept of the line

we know that for x=3 => y=4 then we plug the values we know in the equation of the line:

$y=ax+b=2x+b$

now we use the point we know:

$4=2\cdot3+b$

then solve for b

$b=4-6=-2$

The the y intercept of the line is y=-2