Anyones help would be greatly appreciated...

The graphs:y = x^2 - bx - 14ANDy = -9x + cintersect at

(-1,8)and(-3,10). Find the values ofbandc

Cheers

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- March 30th 2008, 02:08 AMsteph_rSimultaneous quadratic and linear equations - yr 11
Anyones help would be greatly appreciated...

The graphs:**y = x^2 - bx - 14**AND**y = -9x + c**intersect at

**(-1,8)**and**(-3,10)**. Find the values of*b*and*c*

Cheers - March 30th 2008, 02:13 AMMoo
Hello,

I don't know where is b... Nevermind.

You know that the points (-1,8) and (-3,10) belong to both the graphs.

So you just have to replace their values in the expressions of the functions. - March 30th 2008, 02:21 AMsteph_r
- March 30th 2008, 02:30 AMthe wildcat
just substitute (-1,8) and (-3,10) into both equations

e.g.

y=9x+c

at (-1,8)

8= -9 * -1 +c

y=9x+c

at (-3,10)

10= -9 * -3 +c (*=times)