Question

3a+a=20
y+4+y=16
помогите решить уравнение

Answer 1

3a+a=20

4a = 20

a = 20 : 4

a = 5

============

y+4+y=16

2y + 4 = 16

2y = 16 - 4

2y = 12

y = 12 : 2

y = 6

Answer 2

$3a + a = 20 \\ 4a = 20 \\ a = 5 \\ \\ y + 4 + y = 16 \\ 2y + 4 = 16 \\ 2y = 16 - 4 \\ 2y = 12 \\ y = 12$