(i) 108 x 192
= (2 x 2 x 3 x 3 x 3) x (2 x 2 x 2 x 2 x 2 x 2 x 3)
= (22 x 33 ) x (26 x 3)
= 26 + 2 x 33 + 1 (am x an = am+n)
= 28 x 34
(ii) 270
= 2 x 3 x 3 x 3 x 5
= 2 x 33 x 5
(iii) 729 x 64
= (3 x 3 x 3 x 3 x 3 x 3) x (2 x 2 x 2 x 2 x 2 x 2)
= 36 x 26
(iv) 768
= 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 3
= 28 x 3
Using laws of exponents, simplify and write the answer in exponential form:
(i) 32 × 34 × 38 (ii) 615 ÷ 610 (iii) a3 × a2 (iv) 7x×72 (v) (52) ÷ 53 (vi) 25 × 55 (vii) a4 × b4 (viii) (34)3(ix) (220 ÷ 215)×23 (x) 8t ÷ 82
Write equations for the following statements:
(i) The sum of numbers x and 4 is 9.
(ii) 2 subtracted from y is 8.
(iii) Ten times a is 70.
(iv) The number b divided by 5 gives 6.
(v) Three-fourth of t is 15.
(vi) Seven times m plus 7 gets you 77.
(vii) One-fourth of a number x minus 4 gives 4.
(viii) If you take away 6 from 6 times y, you get 60.
(ix) If you add 3 to one-third of z, you get 30