Math Problem ? Im Stuck Help?

Question

In each of the equations below, what is y when x=2? When x=0? Where would the graph of each cross the y-axis?

a) y=3x+15 b) y=3-3x

Answer 1

a) x=2 y=21 crosses the y axis at 15

b) x=2 y= -3 crosses the y axis at 3

Answer 2

to find what y is whe x=2, just substitute the number 2 anywhere you see an 'x'. do the same with 0 for the next part.

Graphs cross the y axis when x = 0, so the answer is the same as in part ii

Answers

a)i. 21 ii. 15 iii. (0,15)

b)i. -3 ii. 3 iii. (0,3)

Answer 3

a) x = 2, y = 21; x = 0, y = 15  crosses at (0,15)

b) x = 2, y = -3; x = 0, y = 3   crosses at (0, 3)