Question

using (x+a) (x+b) = x² + (a+b) x + ab , find
a) 103 × 104
b) 5.1 × 5.2

Answer 1

Answer:

$103 \times 104 = 10712$

$5.1 \times 5.2 = 26.52$

Answer 2

$\underline{\underline{ \huge \red{ \mathfrak{AnSwer}}}}$

★ identity

• (x + a) (x + b) = x² + (a + b)x + ab

__________________________

a) 103 × 104

➪ (100 + 3) × (100 + 4)

➪ (100)² + (3 + 4)100 + 3 × 4

➪ 10000 + 700 + 12

➪10712

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b) 5.1 × 5.2

➪ (5 + 0.1) × (5 + 0.2)

➪ 5² + (0.1 + 0.2)5 + 0.1 × 0.2

➪ 25 + 1.5 + 0.02

➪ 26.52