<span>225^2 =50625</span>
<span>113^2=12769
</span>50625-12769=37856
379856:2=3145
10-2х+8=1+3х
18-1=3х+2
17=5х
х=17/5
х=3,4
mx^2+nx^2+4m+4n+4mx+4nx=x^2(m+n)+4(m+n)+4x(m+n)=(m+n)(x^2+4x+4)=(m+n)(x+2)^2
40с^2-(1+12c+36c^2)+1
40c^2-1-12c-36c^2+1
4c^2-12c
4c(c-3)