A car moving with constant acceleration covers the distance between two points 180 m apart in 6 sec. Its speed as it passes the second  point is 45 m/s. What is its acceleration and its speed at the first point

v² = u² + 2as $\Rightarrow$45² = u² + 2a x 180
2025 = u² + 360a............ (1)
v = u + at ;
45 = u + a × 6
u = 45 – 6a ............ (2)
(1) & (2)$\Rightarrow$2025 = (45 - 6a)² + 360a
$\begin{array}{l}2025=2025+36{\mathrm{a}}^2-540\mathrm{a}+360\mathrm{a}\\ 36{\mathrm{a}}^2=180\mathrm{a}\Rightarrow \mathrm{a}=\frac{180}{36}=5\mathrm{m}/{\mathrm{s}}^2\end{array}$
(2) $\Rightarrow$u = 45 -6 x 5 = 15m/s