©G Dear 2010 – Not to be sold/Free to use Applied Mathematic (Preliminary General 1) Algebra Harder Substitution Stage 6 - Year 11 Press Ctrl-A ©G Dear 2010 – Not to be sold/Free to use

Algebraic Substitution - Simple Replacing pronumerals with numbers. The formula for the speed of a car is v = u + a t Problem: The Porche 911 does a rolling start. Initial speed is 2.8 m/s [approx 10 km/h] and acceleration is 8 m/s2. How long will it take to reach 28 m/s [approx 100 km/h]? v = u + at -2.8 -2.8 28 = 2.8 + 8 x t ÷8 ÷8 25.2 = 8 x t t = 3.2 seconds

Algebraic Substitution - Simple Replacing pronumerals with numbers. The formula for the simple interest is I = P r n Problem: The Porche 911 costs $175 000. The interest rate is 8% (0.08). The interest paid was $84 000. How long was the car loan taken for? I = P r n 84 000 = 175 000 x 0.08 x n ÷14000 ÷14000 84 000 = 14000 x n n = 6 years