Question

вычеслите:
а) 87²-174×67+67²
б) 38-17²
47²-361​

Answer 1

a) 87² - 174 * 67 + 67² = 87² - 2 * 87 * 67 + 67² = (87 - 67)² = 20² = 400

б)$\frac{38^{2}-17^{2}}{47^{2}-361}=\frac{38^{2}-17^{2}}{47^{2}-19^{2}}=\frac{(38-17)(38+17)}{(47-19)(47+19)}=\frac{21*55}{28*66}=\frac{3*5}{4*6}=\frac{15}{24}=0,625$