Question

(3x. +7)² -84x=(3x -7)² please solve step step by step..​

Answer 1

Answer:

Step-by-step explanation:

(3 x +7)² - 84 x = (3 x -7)²

$(3x)^{2} +7^{2}+2(3x)7-84=(3x)^{2} +7^{2}-2(3x)7\\9x^{2} +49+42x-84=9x^{2} +49-42x\\42x+42x=84\\84x=84\\x=\frac{84}{84}\\x=1$