20
a = 20 b = 60 c = 100
a = 6b = 9a + b = 6 + 9 = 15
The answer is 144. The compound operator for (a) and (b) in each pair is a * (a+b). For 9 and 7, this is 9 x (9+7) = 9 x 16 = 144.
Set it up like this: B+9=8+6B+9=14B=5
20
a = 20 b = 60 c = 100
a = 6b = 9a + b = 6 + 9 = 15
Addition is commutative. That is, a + b = b + a for all a, b
The answer is 144. The compound operator for (a) and (b) in each pair is a * (a+b). For 9 and 7, this is 9 x (9+7) = 9 x 16 = 144.
Set it up like this: B+9=8+6B+9=14B=5
A = 1, B = 9
4+5=9
If you mean 3b+9 = 12 then b equals 1
b + 9 = 21 Take the + 9 across the other side of the equals sign. a plus becomes a minus. b = 21 - 9 so... b = 12. This can be checked by setting b to 12 in the first equation b + 9 = 21 12 + 9 = 21 which is correct.
9
b+9=2 sbtract nine both sides b=2-9 b=-7