Question

решите уравнения : 15с +45-12=78 и (6у+14) :2 +15=40

Answer 1

15c+45-12=78
15c=78+12-45
15c=4515
c=3

(6y+14):2+15=40
6y+142+15=40
2(3y+7)|2+15=40
3y=40-22
3y=18
y=6