Answer:
b=9,a=12
Step-by-step explanation:
I solved by substitution:
b = 3/4a ---> plug this into the other equation
a + b = 21 is now a + 3/4a = 21
Reduce: 7/4a = 21
a = 12
Now solve for b:
b=3/4a is now b=3/4(12)
b=9
a=12 b= 9
did the quiz
1) 600-t
2) 600-t=65
=>t=535
b
is the situation could the expression model.
6 i think
