Expand (2x + 5)(9x - 2).
Use the FOIL method:F - FIRST: the first term in either bracket, multiply: 2x(9x) = 18x2. O - OUTSIDE: the terms further from the centre of the brackets, multiply: 2x(-2) = -4x. I - INSIDE: the terms closer to the centre of the brackets, multiply: 5(9x) = 45x. L - LAST: the latter terms in either bracket, multiply: 5(-2) = -10. Now add the expressions from the four parts: 18x2 - 4x + 45x - 10 = 18x2 + 41x - 10.
AH
Related Maths GCSE answers
All answers ▸Celine has £5 to buy pens and rubbers. Pens are 18p each. Rubbers are 30p each. She says “I will buy 15 pens. Then I will buy as many rubbers as possible. With my change I will buy more pens.” How many pens and how many rubbers does she buy? [5 marks]
If Tom flips a coin 3 times, what is the probability the result are heads, heads, heads, or tails,heads, tails? (assuming we have a fair coin)
Maths A-level Question, Rates of change involving a cylindrical vessel.
Find the roots of the formula x^2 + 4x + 3 by factorising.