Expand the brackets: (x + 5)(x - 3)?
An easy way to remember how to expand double brackets is using FOIL. FOIL stands for First, Outer, Inner, and Last. First indicates that we multiple the first two terms of each bracket (x * x = x2). Outer multiples the outer terms ( x * -3 = -3x). Inner multiplies the inner terms (5 * x = 5x). Finally, Last multiplies the last terms of each bracket (5 * -3 = -15). Our answer is the sum of the individual FOIL results: x2 + (-3x) + 5x + (-15) = x2 + 2x - 15.
DW
Related Maths GCSE answers
All answers ▸Find the solutions to the simultaneous equations
I find the percentage questions really hard, how do I answer the questions that will come up in exams?
Calculate the length of the hypotenuse of a right-angled triangle when the other two sides measure 6cm and 9cm.
What is a product of prime factors?