1.
5a * 4 = 14 − 4 20a = 10 a = 10 : 20 a = 0,5
2.
(2a + 1) * (−1) = −6a + 2 * (−1) − 13 −2a − 1 = −6a − 2 − 13 −2a + 6a = −2 − 13 + 1 4a = −14 a = −14 : 4 a = −3,5