Question

Решите срочно Сор по алгебре ​

Answer 1

$1.\;2x^2-8=2(x^2-4)=2(x-2)(x+2)\\\\2.\;a=x+2\\3a^2=3(x+2)^2=3(x^2+4x+4)=3x^2+12x+12\\\\3.\;a)\;47^2-2\cdot47\cdot17+17^2=(47-17)^2=30^2=900\\b)\;\frac{16^2-12^2}{13^2-6^2}=\frac{(16-12)(16+12)}{(13-6)(13+6)}=\frac{4\cdot28}{7\cdot19}=\frac{112}{133}=\frac{16}{19}\\\\4.\;x,\;x+4\\(x+4)^2-x^2=32\\x^2+8x+16-x^2=32\\8x=16\\x=2\\2\;u\;6$