Номер 1298

1) 2(3х – 5) + 4х = 2 • 3х – 2 • 5 + 4х = 6х – 10 + 4х = 10х – 10

2) –(7а + 8) + 3а = –7а – 8 + 3а = –4а – 8

3) 7х + (х – 3) = 7х + х – 3 = 8х – 3

4) 2у – 3(у – 5) = 2у – 3у – 3 • (–5) = 2у – 3у + 15 = 15 – у