Question

Solve by using Identity:

a) 103 × 104. ; b) 9.7 × 9.8​

Answer 1

Answer:

Just apply the formula and you will get the value

Answer 2

Answer:

a) 103 × 104 = 10712

b) 9.7 × 9.8 = 95.06

Step-by-step explanation:

a) 103 × 104

(100 + 3)(100 + 4)

Using the identity,

(x + a)(x + b) = x² + (a + b)x + ab

Thus,

(100 + 3)(100 + 4)

100² + ((3 + 4)100) + (3 × 4)

10000 + (7 × 100) + 12

10000 + 700 + 12

10712

Thus,

103 × 104 = 10712

b)

9.7 × 9.8

(10 - 0.3)(10 - 0.2)

Using the identity,

(x - a)(x - b) = x² - (a + b)x + ab

So,

(10 - 0.3)(10 - 0.2)

10² - (0.3 + 0.2)10 + (0.3 × 0.2)

100 - 5 + 0.06

95 + 0.06

= 95.06

Thus,

9.7 × 9.8 = 95.06

Hope it helped and believing you understood it........All the best