Need quick math help!

Discussion in 'Community Discussion' started by twistedlegato, Jan 28, 2007.

1. twistedlegato macrumors 65816

Joined:
Jun 15, 2006
#1
I know this is probabley very easy for most of you, but let i remind you, i am in pre-algabra, though i am in a gifted class!

Given the equations, determine the slope of the line.
Give the y-intercept.

1) 5x+2y=7

2)7x+3y=9

Thanks alot!

Joined:
May 16, 2006
Location:
London
3. twistedlegato thread starter macrumors 65816

Joined:
Jun 15, 2006
#3
Can you explain?

4. ®îçhå®? macrumors 68000

Joined:
Mar 7, 2006
#4
1. Gradient -2.5, y intercept 3.5
2.Gradient -2 and 1/3, y intercept 3
Is this correct or am i being really stupid??

Rats just beaten. Make the integer infront of y=1.
y= mx + c where m is the gradient and c is the y intercept. Make x=0 and the y intercept is obvious and the gradient is the integer infront of the x. Is this explained well enough??

5. psychofreak Retired

Joined:
May 16, 2006
Location:
London
#5
There are two ways to find gradient and point of intercept. The easiest for this solution is:

y=mx + c

(m being the gradient, and c the y intercept)

rearrange the equations to y=....
find the number of x's (this is the gradient, and the other number, the y intercept)

1. y= -2.5x + 3.5
2. y= -7/3x + 3

6. psychofreak Retired

Joined:
May 16, 2006
Location:
London
#6
Too late biznitchwizzle....oh how I've longed to say that...

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Jun 15, 2006
8. ®îçhå®? macrumors 68000

Joined:
Mar 7, 2006
#8
By doing AS level maths and being taught it (and also being in an express set)

9. bearbo macrumors 68000

Joined:
Jul 20, 2006
#9
5x + 2y = 7
=>2y = 7-5x
=>y = 3.5-2.5x

3.5 is intercept, -2.5 is slope

7x + 3y = 9
=>3y = 9 - 7x
=> y = 3 - 7/3x

3 is intercept, -7/3 is slope

10. twistedlegato thread starter macrumors 65816

Joined:
Jun 15, 2006
#10

AHHHH!

I learned to do it with fraction, not decimals so i was cunfused!

Thanks everyone!