Question

What is the x and y intercept of y=3x-15 and is (2,-9) a solution?

Answer 1

Answer: y intercept (0,-15), x intercept (5,0), yes, (2,-9) is a solution

Explanation:

the y intercept is when x=0, so plug in 0 for x -> y=3(0)-15

y=-15, y intercept is (0,-15)

the x intercept is when y=0

so plug in 0 for y -> 0=3x-15

then solve for x,

add 15 to both sides -> 15=3x

divide both sides by 3, 5=x

x intercept is (5, 0)

to test if (2, -9) solution, lets plug in 2 for x and see if we get an answer of -9

so y=3(2)-15

y=6-15

y=-9

so yes, (2,-9) is a real solution