boat traveled 180 kilometers each way downstream and back. The trip downstream took 9 ours. The trip back took 45 hours. Find the speed of the boat in still water and the speed of th urrent.

\( 5 / 15 \) Simplify the expression: \( -2 x^{2}-x+1-x^{2}+3 x-5 \)

Find the square of 45 . (1 point)

Estimate the quotient. \( 5 2 \longdiv { 3 8 6 } \) The estimate is: \( \square \)

15 Fungsi \( f \) ditakrifkan sebagai \( f(x)=\frac{2 x}{x+3} \). A function \( f \) is defined by \( f(x)=\frac{2 x}{x+3} \) (a) Cari \( f^{\prime}(1) \). Find \( f^{\prime}(1) \). (b) Seterusnya, anggarkan nilai bagi \( \frac{2(1.01)}{1.01+3} \). Hence, estimate the value of \( \frac{2(1.01)}{1.01+3} \).

Simplify \( \frac{y^{2}-4 y+4}{y-2} \div \frac{2 y^{2}-8}{4 y} \)