Question

Find the value of 'x'such that
28.
72x x75 =715​

Answer 1

Answer:

★ ANSWER :

x = 5

Step-by-step explanation:

★ QUESTION :

Find the value of ‘x’ such that

${7}^{2x} \: \times \: {7}^{5} \: = \: {7}^{15}$

★ CONCEPT USED :

${a}^{m} \: \times \: {a}^{n} \: = \: {a}^{m \: + \: n} \\ \\ {a}^{m } \: \div \: {a}^{n} \: = \: {a}^{m \: - \: n}$

★ SOLUTION :

${7}^{2x} \: \times \: {7}^{5} \: = \: {7}^{15} \\ \\ \implies \: {7}^{2x \: + \: 5} \: = \: {7}^{15} \\ \\ \implies { \not \cancel7}^{2x \: + \: 5} \: = \: { \not \cancel7}^{15} \\ \\ \implies \: 2x \: + \: 5 \: = \: 15 \\ \\ \implies \: 2x \: = \: 15 \: - \: 5 \\ \\ \implies \: 2x \: = \: 10 \\ \\ \implies \: x \: = \: \cancel\frac{10}{2} \\ \\ \implies \: x \: = \: 5$

★ ANSWER :

x = 5

HOPE IT HELPS YOU !

THANKS !

Answer 2

$\pink\bigstar$Answer:

$\boxed{x \: = \: 5 }$

$\red\bigstar$ Given:

• $\sf \: {7}^{2x} \times \: {7}^{5} \: = \: {7}^{15}$

$\bigstar$To find:

• The value of x.

$\bigstar$ Solution:

$\sf \: {7}^{2x} \: \times \: {7}^{5} = \: {7}^{15} \\ ( \because \: \sf we \: know \: that \: \: {a}^{b} \: \times \: {a}^{c } \: = \: {a}^{b \: + \: c} ) \\ \implies \: \sf \: {7}^{2x \: + \: 5} \: = \: {7}^{15} \\ ( \because \: \sf \: we \: know \: that \: when \: bases \: are \: same \: then \: powers \: are \: equal) \\ \implies \sf\: 2x \: + \: 5 \: = \: 15 \\ \sf\implies \: 2x \: = \: 15 \: - \: 5 \\ \sf \: \implies \: 2x = \: 10 \\ \sf \: \implies x \: = \: \dfrac{10}{2} \\ \sf\implies \: \boxed{ \: x \: = \: 5}$

$\bigstar$ Concepts Used:

$\bullet \: \: {a}^{b} \: \times \: {a}^{c } \: = \: {a}^{b \: + \: c} \: \sf \: \\ </p><p> \bullet\sf \: when \: bases \: are \: same \: then \: powers \: are \: equal$