(2y – 4y3 +6y -3 ) (Ey2 +y -3)
Answers
Answer:
these work before moving on:
(a) 3a + 12b – 5a + 7b – 2a = – 4a + 19b
(b) x² + 5x – 5 + 4x² – 3x + 5 = 5x² + 2x (these two terms can not be added as one is x and the other is x²)
(c) 2p + 3pq – 5pq² + 6p – pq = 8p + 2pq – 5pq²
Practice Questions
Work out the answer to each question then click on the button marked to see if you are correct.
Simplify these expressions by collecting like terms:
(a) 3p + 6q – 5p + 3q
(b) x3 – 4x2 + 7x – 3 + 7x2 – 9x + 1
(c) ab2 + 3ab - 3a + 2ab2 - 5ba + 4a
Laws of Indices
Rules to learn
positive powers an means multiply together n lots of a
e.g. a5 = a × a × a × a × a
multiplying powers If the bases are the same then you add the powers: am × an = a(m + n)
e.g. x5 × x3 = x8
dividing powers If the bases are the same then you subtract the powers: am ÷ an = a(m – n)
e.g. y2 ÷ y6 = y– 4
This also works for powers in fractions: e.g. p7 = p3 p4
powers of powers The powers are multiplied: (am)n = a(mn)
e.g. (z2)5 = z10
special powers a1 = a and a0 = 1
e.g. b4 ÷ b3 = b1 = b
e.g. d 3 × d – 3 = d 0 = 1
multiplying terms To multiply terms, multiply the coefficients to get the new coefficient then multiply each letter in turn:
e.g. 3x2 × 5x3 = 15x5
e.g. 4xy 2 × x3 × 3x