KnowledgeBoat Logo
|

Mathematics

Express each of the following in exponential notation :

(i) (521)3×(521)8\Big(\dfrac{5}{21}\Big)^3 \times \Big(\dfrac{5}{21}\Big)^8

(ii) (73)11×(73)13\Big(\dfrac{-7}{3}\Big)^{11} \times \Big(\dfrac{-7}{3}\Big)^{13}

(iii) (1343)7÷(1343)2\Big(\dfrac{13}{43}\Big)^7 ÷ \Big(\dfrac{13}{43}\Big)^2

(iv) (1635)16÷(1635)3\Big(\dfrac{-16}{35}\Big)^{16} ÷ \Big(\dfrac{-16}{35}\Big)^3

(v) (715)12÷(715)15\Big(\dfrac{-7}{15}\Big)^{12} ÷ \Big(\dfrac{-7}{15}\Big)^{15}

(vi) (124)13÷(124)16\Big(\dfrac{1}{24}\Big)^{13} ÷ \Big(\dfrac{1}{24}\Big)^{16}

Exponents

1 Like

Answer

(i) (521)3×(521)8\Big(\dfrac{5}{21}\Big)^3 \times \Big(\dfrac{5}{21}\Big)^8

Using the multiplication rule, we add the exponents: 3 + 8 = 11.

(521)3×(521)8=(521)3+8=(521)11\therefore \Big(\dfrac{5}{21}\Big)^3 \times \Big(\dfrac{5}{21}\Big)^8 \\[1em] = \Big(\dfrac{5}{21}\Big)^{3+8} \\[1em] = \Big(\dfrac{5}{21}\Big)^{11}

Hence, the answer is (521)11\Big(\dfrac{5}{21}\Big)^{11}

(ii) (73)11×(73)13\Big(\dfrac{-7}{3}\Big)^{11} \times \Big(\dfrac{-7}{3}\Big)^{13}

Using the multiplication rule, we add the exponents: 11 + 13 = 24.

(73)11×(73)13=(73)11+13=(73)24\therefore \Big(\dfrac{-7}{3}\Big)^{11} \times \Big(\dfrac{-7}{3}\Big)^{13} \\[1em] = \Big(\dfrac{-7}{3}\Big)^{11+13} \\[1em] = \Big(\dfrac{-7}{3}\Big)^{24}

Hence, the answer is (73)24\Big(\dfrac{-7}{3}\Big)^{24}

(iii) (1343)7÷(1343)2\Big(\dfrac{13}{43}\Big)^7 ÷ \Big(\dfrac{13}{43}\Big)^2

Using the division rule, we subtract the exponents: 7 - 2 = 5.

(1343)7÷(1343)2=(1343)72=(1343)5\therefore \Big(\dfrac{13}{43}\Big)^7 ÷ \Big(\dfrac{13}{43}\Big)^2 \\[1em] = \Big(\dfrac{13}{43}\Big)^{7-2} \\[1em] = \Big(\dfrac{13}{43}\Big)^5

Hence, the answer is (1343)5\Big(\dfrac{13}{43}\Big)^5

(iv) (1635)16÷(1635)3\Big(\dfrac{-16}{35}\Big)^{16} ÷ \Big(\dfrac{-16}{35}\Big)^3

Using the division rule, we subtract the exponents: 16 - 3 = 13.

(1635)16÷(1635)3=(1635)163=(1635)13\therefore \Big(\dfrac{-16}{35}\Big)^{16} ÷ \Big(\dfrac{-16}{35}\Big)^3 \\[1em] = \Big(\dfrac{-16}{35}\Big)^{16-3} \\[1em] = \Big(\dfrac{-16}{35}\Big)^{13}

Hence, the answer is (1635)13\Big(\dfrac{-16}{35}\Big)^{13}

(v) (715)12÷(715)15\Big(\dfrac{-7}{15}\Big)^{12} ÷ \Big(\dfrac{-7}{15}\Big)^{15}

Using the division rule, we subtract the exponents: 12 - 15 = -3.

(715)12÷(715)15=(715)1215=(715)3[The power is negative, so we take the reciprocal]=(157)3\therefore \Big(\dfrac{-7}{15}\Big)^{12} ÷ \Big(\dfrac{-7}{15}\Big)^{15} \\[1em] = \Big(\dfrac{-7}{15}\Big)^{12-15} \\[1em] = \Big(\dfrac{-7}{15}\Big)^{-3} \quad \text{[The power is negative, so we take the reciprocal]} \\[1em] = \Big(\dfrac{-15}{7}\Big)^3

Hence, the answer is (157)3\Big(\dfrac{-15}{7}\Big)^3

(vi) (124)13÷(124)16\Big(\dfrac{1}{24}\Big)^{13} ÷ \Big(\dfrac{1}{24}\Big)^{16}

Using the division rule, we subtract the exponents: 13 - 16 = -3.

(124)13÷(124)16=(124)1316=(124)3[The power is negative, so we take the reciprocal]=243\therefore \Big(\dfrac{1}{24}\Big)^{13} ÷ \Big(\dfrac{1}{24}\Big)^{16} \\[1em] = \Big(\dfrac{1}{24}\Big)^{13-16} \\[1em] = \Big(\dfrac{1}{24}\Big)^{-3} \quad \text{[The power is negative, so we take the reciprocal]} \\[1em] = 24^3

Hence, the answer is 243

Answered By

1 Like


Related Questions