Respuesta :
answer is B: 150
write two equations
r+s=190
4r+3s=720
solve by substitution
the get r=150 s=40
write two equations
r+s=190
4r+3s=720
solve by substitution
the get r=150 s=40
Answer:
150
Step-by-step explanation:
So if we rearrange the second equation we can get:
s = 190 - a
Now we substitute this into the first equation:
4a + 3(190 - a) = 720
4a + (570 - 3a) = 720
4a + 570 - 3a = 720
4a - 3a = 720 - 570
a = 150