Вправи: 145

145. Виконайте дію:

1) 5a7 • 2120a2 = 5a • 217 • 20a2 = 34a;

2) 3,514a2 • 4a35b = 3,5 • 4a314a2 • 5b = 14a14 • 5b = a5b;

3) c230 • 20cm = c2 • 2030 • cm = 2c3m;

4) –3m5a2 • a9m2 = –3am5a2 • 9m2 = –115am;

5) 4x27p • (–21p8x3) = –4x2 • 21p7p • 8x3 = –32x;

6) –5x27y3 • (–21y225x) = 5x2 • 21y27y3 • 25x = 3x5y.