XY plane. Exam pack 2

Hi prata,

You can deal with this prompt by either drawing a picture or by just creating an equation based on the facts that you know.

The slope-intercept formula for a line is Y = MX + B

From the prompt, we know that the slope is 3 and the X-INTERCEPT is 3 (meaning that X=3 when Y=0)

Y = MX + B
Y = 3X + B

0 = 3(3) + B
0 = 9 + B
-9 = B

So the Y-intercept is -9

Final Answer: E

GMAT assassins aren't born, they're made,
Rich

prata wrote:In the xy-plane, a line has slope 3 and x-intercept 3. What is the y-intercept of the line?

1. 9

2. -3

3. 0

4. 3

5. 9

We are given that the line has slope 3 and x-intercept 3 and we need to find its y-intercept. Recall that the slope-intercept form of a line is y = mx + b where m is the slope and b is the y-intercept. Therefore, we need to find the value of b. Since the slope is 3, we know that the line has the form y= 3x + b.

Furthermore, the x-intercept is 3, which means the line passes through the point (3, 0). Thus, we can substitute 3 in for x and 0 for y to find the value of b:

y = 3x + b

0 = 3(3) + b

0 = 9 + b

b = -9

Since the value of b is -9, the y-intercept of the line is -9.

(Note: There is a typo in the choices since both choices 1 and 5 are 9. I think one of them should be -9.)