Question

simplify the following expressions. (7+5x) (7+5x) -(2x-3) (2x-3)​

Answer 1

Answer:

$21x^{2} + 58x + 40$

Step-by-step explanation:

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

applying the identity- $(a+b)^{2} and (a-b)^{2}$

we can write-

• $[(7+5x)^{2} ] - [(2x-3)^{2} ]$

• $[(7)^{2}+ (5x)^{2}+ 2(7)(5x) ] - [(2x)^{2}+(-3)^{2} - 2(2x)(-3) ]$

• $[(49) + (25x^{2}) + (70x) ] - [(4x^{2} )+ (9) - (-12x)]$

• $[49 + 25x^{2} + 70x ]-[4x^{2} + 9 + 12x ]$

by opening the brackets-

• $49 + 25x^{2} +70x -4 x^{2} - 9 - 12x$

by arranging them accordingly,

• $25x^{2} - 4x^{2} +70x - 12x +49-9$

• $21x^{2} + 58x + 40$