Math questions?

Question

Can someone help clarify this please, for equation of a line passing through (-2,3) slope 2/3, i get up to the point where 3 + 4/3 = b, but don't get how this equals 13/3... can someone explain that part to me?

also, similarly on an equation of a line passing through (3,-1) and is perpendicular to 4y=3x+5, I get lost and come up with something like y=-4/3x and cant figure the rest out... any help is highly appreciated, thanks.

Answer 1

I can answer the first part.
4/3 + 3 ==>
Take the Least common multiple of da denominators surely you'll know that:
the least common multiple (LCM) = 3*1 = 3
So put the denominator. Now
Take 4 and the denominator is 3.
You should check 3 multiplied by what gives you the LCm which is three.
3*1=3
So multiply 4*1
Then Take the next numerator that is 3. Its denominator is1. 1 multiplied by 3 gives you 3. So take 3 and multiply with numerator that is 3*3=9
Take (4*1 + 3*3) and divide the whole thing by 3.
(4 + 9)/3 ==> 13/3.
Sorry can't help you with the other one

Answer 2

First problem: the general form is y = 2/3 x + c, with c to be determined. Using the given point, we have 3 = 2/3 (-2) + c, or 3 + 4/3 = c, or c = 13/3.

Second: The given line is y = 3/4 x + 5/4, so the slope of the perpendicular is -4/3. Thus, we have y = -4/3 x + c, and at the given point we have -1 = -4/3(3) + c, or -1 = -4 + c, or c = 3. Final result: y = -4/3 x + 3.

Answer 3

You are SOOOOOO close...

I'd use the form, y = mx + b where m is the slope
You know m (the slope) = 2/3.
And you know an x and y that satisfy the equation, -2 and 3 respectively.
So: 3 = (2/3)(-2) + b
3 = -4/3 + b
9/3 = -4/3 + b
13/3 = b This is the part of the equation for the line that you didn't know before.
So now you know m = 2/3 AND
b = 13/3
This is where you got stumped.

Rember the form y = mx + b that we started with?
y = 2x/3 + 13/3
If I were a teacher, I'd prefer 3y = 2x + 13 (I don't like seeing fractions laying around.)

Answer 4

If the slope is 2/3, then for every 3 you increase on the x axis, you increase 2 on the y axis.

m = (y2 - y1) / (x2 - x1)

We have a point (-2,3) and another point (0,b). We are solving for b.

2/3 = (b - 3) / (0 - -2) = (b - 3) / 2
2 * 2/3 = b - 3
4/3 + 3 = b
b = 4-1/3

y = (2/3)x + 4-1/3

Test this

y = (2/3)(-2) + 4-1/3
y = -4/3 + 4-1/3 = -1-1/3 + 4-1/3 = 3

Answer 5

1. 3 + 4/3 = 9/3 + 4/3 = (9+4)/3 = 13/3

Answer 6

3 + 4/3 to an improper fraction is 3*3+4 for new numerator so
13/3

for second y = -4/3x + 5 is slope form of line that is perpendicular to the line you want, so slope of line you want is -3/4

Answer 7

hmmmm....math sucks. frankly i dont really care about it. I'd guess.