Thread: GR9 Math Exam Review

How would i find the x intercept of the following:

a)
b)
c)
d)

Thanks guys!

To find the x-intercept, set y to 0.

a) This one has no x-intercept, y is always -5 so it never crosses the x axis (which is defined by y=0).

b) 0=-3x+9
3x=9
x=3

So the x intercept is (3,0) or just 3.

c) 2x+3(0)-6=0
2x-6=0
2x=6
x=3

Same answer as b).

d) x is always equal to -4 regardless of y, so the x intercept is (-4,0).

Hope that helps.

How would i find the x intercept of the following:

a)
b)
c)
d)

Thanks guys!

hi
In a.) line is parallel to x-axis
In b.) and c.) put y=0
In d.) answer is in the question

Originally Posted by JD-Styles

To find the x-intercept, set y to 0.

a) This one has no x-intercept, y is always -5 so it never crosses the x axis (which is defined by y=0).

b) 0=-3x+9
3x=9
x=3

So the x intercept is (3,0) or just 3.

c) 2x+3(0)-6=0
2x-6=0
2x=6
x=3

Same answer as b).

d) x is always equal to -4 regardless of y, so the x intercept is (-4,0).

Hope that helps.

Thanks alot you guyz! I just have one more thing... what would be the y-int for d then?

Originally Posted by princevisram

Thanks alot you guyz! I just have one more thing... what would be the y-int for d then?

There is none. For the y intercept we need x=0 so it cannot intersect with x=-4.

Originally Posted by JD-Styles

There is none. For the y intercept we need x=0 so it cannot intersect with x=-4.

K Thanks... 1 more question

in y=mx+b form, how would you write y+3x=10?

would it be y=3x-10 or y=3x+10?

Originally Posted by princevisram

K Thanks... 1 more question

in y=mx+b form, how would you write y+3x=10?

would it be y=3x-10 or y=3x+10?

y=-3x+10

y=-3x+10

Originally Posted by JD-Styles

y=-3x+10

Now, what about ? How do you know which one is y and which one is slope?

Originally Posted by princevisram

Now, what about ? How do you know which one is y and which one is slope?

Depends on what t and d represent. I would assume that t stands for time and d stands for distance, in which case d would be you dependent variable (y).

y is always the variable that depends on the other one. For example if I had the equation p-3s-5=0, where p is the profit and s is the number of sales, well obviously my profit depends on the number of sales so p=y and s=x so I'd write p=3s+5.

Hope that all makes sense.

Originally Posted by JD-Styles

Depends on what t and d represent. I would assume that t stands for time and d stands for distance, in which case d would be you dependent variable (y).

y is always the variable that depends on the other one. For example if I had the equation p-3s-5=0, where p is the profit and s is the number of sales, well obviously my profit depends on the number of sales so p=y and s=x so I'd write p=3s+5.

Hope that all makes sense.

You are sooo amazing!