Math Help Please?

Question

its taken me for ever please help me
Evaluate each function for x=3
f(x)=2x-15
g(x)=2/3x-1

Find the slope of the line parallel to the graph of each equation
6x=2y=4
y=-1/2x+1

Find the slope of thhe line perpendicular to the graph of each equation.
3x+2y=-5
y=-5/2x+11

If u cant do them all its ok but i reallly need help.
thanks to anyone who does help = )

Answer 1

For the first 2, just gotta plug in 3 for every x you see...

f(3) = 2 (3) - 15 = -9
g(3) = (2/3) (3) - 1 = 1

The next 2, you need to solve for y so it's in the form y = mx+b. lines are parallel if they have the same slope ( m )

The first one you might want to relook since there are two equal signs
In the second, the slope of the line is -1/2.. so a line with a slope of -1/2 is perpendicular

The last 2, it's the same idea as the 3rd and 4th. Put each equation into y=mx+b form. m is your slope. For perpendicular lines you need the negative reciprocal

2y=-3x-5
y=-(3/2)x - (5/2)

slope here is -3/2... the negative recriprocal is 2/3

do the same for the 6th.. y=mx+b, then negative recriprocal

Answer 2

For the first two, simply substitute in x=3 in the expressions.

f(3)=2(3)-15=6-15= -9
g(3)=2/3(3)-1 = 2/9-1 = 2/8 = 1/4

For these, you have to put the lines into the form y=mx+ b where m is the slope. If the line is parallel, it is the same. If it is perpendicular, it is the negative reciprocal.

6x=2y=4

2y= -6x+4
y= -3x+2

-3 is the slope parallel to the graph.

y=-1/2 + 1

Already in the mx+b form. -1/2 is the slope paralle.

3x+2y=5

y = -3/2x + 5/2

2/3 is the slope perpendicular.

Last one, y=-5/2x+1, -2/5 is the slope perpendicular.

Hope that helps.

Also, e-mail me or contact me if you would like further help. Always glad to provide support.

Answer 3

f(x)= 2x - 15
2(3) - 15
6-15
= -9

g(x)= 2/3x - 1
2/3 (3) - 1
2-1
= 1


the slope of the line is the gradient also known as 'm' in the formula y= mx + c
so in y= -5/2x + 11
y= m x + c
m= -5/2 which is the slope

and in 3x + 2y= -5
change to y= mx + c

2y= - 3x -5
y= -3/2x - 5/2
y= -3/2x - 2.5
y= m x + c formula applies
so m is -3/2 whicj\h is the slope


in the one with y= -1/2x + 1
y = m x + c formula is here
m is -1/2 which is the gradient or slope here

6x= 2y = 4
so here it can be y= mx + c
the slope is with x in mx
so the slope is= 6


so there! it's been a while since i've done maths like this so please forgive me if i've made any mistakes! good luck!

Answer 4

Well, my dear, there is always a way helping you to understand all this thing and be it in your memory forever. We can give guidance and answer, but you wouldn't have a chance to understand. Learn from other is always faster than learning by yourself. But Basic is still a Basic and need to understand by yourself prior in learning from others. At one point in your future may face dilemma if more than 2 answer is posted for your simple question. If you do not have a strong basic that being learnt by yourself, how do you justify which answer is correct?

To get you on par, the best thing is using a graph paper and draw the curves of the equation. From there, you will begin to learn the basic faster then anyone.

You may also learn the Differentiation (Dy/Dx) to find your curve.....

Remember the best kung fu is all depend on how firm you stand on the ground. :)

Answer 5

Know this rule: 1) for x replace it with 3
2) Put - 1/2x + 1 in place of y
3) The same as for #2
Now you just solve for x assuming you can cross multiply.
And can you manipulate the times table in your head? Good luck.

Answer 6

f(x)=2x-15 that is -9
next one is 2

thats all I know good luck with the slopes

Answer 7

It looks like you've posted math questions a lot. You should probably ask you teacher for help,ask your parents,or get a tutor.