Question

(7+5x )(7+5x) - (2x-3)(2x-3)

Answer 1

Answer:

use (a+b

Step-by-step explanation:

use (a+b)^2 = a^2+b^2+2ab

so 49 +25x^2 +70x -(4x^2+9-12x)

40+21x^2+82x

Answer 2

Step-by-step explanation:

$(7 + 5x)(7 + 5x) - (2x - 3)(2x - 3) \\ = (7 + 5x) {}^{2} - (2x - 3) {}^{2} \\ = 7 {}^{2} + 2 \times 7 \times 5x + (5x) {}^{2} -( (2x)^{2} - 2 \times 2x \times 3 + 3 {}^{2} ) \\ = (49 + 70x + 25x ^{2} ) - (4x ^{2} - 12x + 9) \\ = 49 + 70x + 25x {}^{2} - 4x {}^{2} + 12x - 9 \\ = 40 + 82x + 21x {}^{2} \\ = 21x {}^{2} + 82x + 40$

$that \: may \: help$