Question

1)20a+(a-10)²

2)(3m+5)²-9m²
3)(x+4)²-8(x+2)
4)(2a-7b)²-(4a²+49b²)
Упростить,СРОЧНО​​

Answer 1

$\displaystyle 1)20a+(a-10)^2=20a+a^2-20a+100=a^2+100\\\\ 2)(3m+5)^2-9m^2=9m^2+30m+25-9m^2=30m+25\\\\ 3)(x+4)^2-8(x+2)=x^2+8x+16-8x-16=x^2\\\\ 4)(2a-7b)^2-(4a^2+49b^2)=4a^2-28ab+49b^2-4a^2-49b^2=-28ab$