16r²-24rs+9s²-49=(4r-3s)²-7²=(4r-3s-7)(4r-3s+7)
s²+4st+4t²-k²-10kc-25c²=(s+2t)²-(k+5c)²=(s+2t+k+5c)(s+2t-k-5c)
16r²-24rs+9s²-49=(4r-3s)²-7²=(4r-3s-7)(4r-3s+7)
s²+4st+4t²-k²-10kc-25c²=(s+2t)²-(k+5c)²=(s+2t+k+5c)(s+2t-k-5c)