Thread: Quadratic formula questions

Can someone help me solve these questions i'm finding it really difficult.....

SIMULTANEOUS EQUATION

2x+y=7
3x-y=3

SOLVE ALGEBRAICALLY

(a) y= x^2 + 3x -8
y= x - 5

(b) Write down the formula to find the roots of the equation
(c) Use the formula to find the roots of: 3x^2-9x-16=0

Originally Posted by GAVREED2

2x+y=7
3x-y=3

...(1)
...(2)

Using (1) and subbing this into (2)

Can you finish it?

Originally Posted by GAVREED2

.....



SOLVE ALGEBRAICALLY

(a) y= x^2 + 3x -8
y= x - 5

Can you have a go from here? (if not my answer to the next question might help!)

Originally Posted by GAVREED2

(c) Use the formula to find the roots of: 3x^2-9x-16=0

For