Sagot :
Alright, lets assume x = 5. 2 X 5 = 10 - 7 = 3, then 3 squared is 9. Ans. = 9.
[tex](2x-7)^2=(2x-7)(2x-7)=2x\cdot2x+2x\cdot(-7)-7\cdot2x-7\cdot(-7)\\\\=4x^2-14x-14x+49=4x^2-28x+49\\\\\\or\\\\\\(2x-7)^2=(2x)^2-2\cdot2x\cdot7+7^2=4x^2-28x+49\\\\(a-b)^2=a^2-2ab+b^2[/tex]