Question

(5 + 7с) ∙ 15 = −30 помогитиии)

Answer 1

(5+7с)*15=-30
75+105с=-30
105с=-30-75
105с=-105
с=-1

Answer 2

(5+7с)×15=-30

5×15=75

7с×15=105с

75+105с=-30

105с=-30-75

105с=-105

с=-105÷105

с=-1