1.The braking distance of a car is directly proportional to the square of its speed. When the speed is p metres per second, the braking distance is 6m. When the speed is increased by 300%, find

a)an expression for the speed of the car

b)the braking distance

c)the percentage increase in the braking distance

2.Solve $\displaystyle |x^2+3x-4|=6$

for 1(a), what i tried to do was,

let braking distance be d, speed be s and constant be k.

$\displaystyle d=ks^2$

$\displaystyle 6=kp^2$

$\displaystyle k=\frac{6}{p^2}$

speed increased by 300%,

$\displaystyle d=ks^2$

$\displaystyle s=\sqrt{\frac{d}{\frac{6}{p^2}}}$

this doesn't seem right..........==

for question2, is there a way to solve it without drawing the graph??