а) 63+(78-х)•5=363
б) (54•х+2760)=42
помогите плиз

Как-то так.

а) 63 + (390 - 5x) = 36363 + 390 - 5x = 363-5x = 363 - 390 - 63-5x = - 905x = 90x = 90/5 = 18б) 54x + 2760 = 4254x = 42 - 276054x = −2718x = −2718/54 = −50,(3)