Question

Find the square of ( 4a – 5b)

Answer 1

$(4a - 5b)$

We have to find the square of Above question:

$(4a - 5b) {}^{2}$

$(a - b) {}^{2} = a {}^{2} + b {}^{2} - 2ab$

$(4a) {}^{2} + (5b) {}^{2} - 2 \times 4a \times 5b$

$16a {}^{2} + 25b {}^{2} - 40ab$

Answer 2

Answer:

We know that ,

$( {a - b})^{2} = ( {a})^{2} - 2ab + ({b})^{2}$

So...

$({4a - 5b})^{2} = ({4a})^{2} - 2(4a)(5b) + ( {5b}) ^{2}$

We get,

$({4a - 5b})^{2} = 16 {a}^{2} - 40ab + 25 {b}^{2}$