4b
b+b+b+c+c+c+c =3b+4c
b + b + b + c + c + c + c = 3b + 4c
a-b+a-b+2b+a = 4a
3b
b + a + b - a = 2b
It is: b+b+b = 3b
b + b + b + 7 = 223b + 7 = 223b = 15b = 5
a+a+a+a+b+b - add the like terms =4a+2b 4a and 2b cannot be added because they are not like terms.
a+b+2+3=5+a+b
That factors to (a + 1)(a + b) a = -1, -b b = -a
It is B+a+5