Answer:
7.52
Step-by-step explanation:
5.37 + x = 12.89
In order to solve this equation, we must isolate the variable, x.
1.) To do this, subtract 5.37 on both sides of the equation.
5.37 + x = 12.89
-5.37 -5.37
x = 7.52
Therefore, x = 7.52
it's either a or b, not sure but I think it's b
Going upstream: 432 km / 6 hours = 72 km/h
Going downstream: 384 km / 4 hours = 96 km/h
Going upstream against the current means that the effective speed is:
r_boat - r_current = 72
Meanwhile, going downstream with the current means;
r_boat + r_current = 96
Adding both equations (to cancel out r_current) gives:
2r_boat = 72 + 96
r_boat = 84 km/h
Substituting back into one of the original equations: r_current = 12 km/h.
I'm pretty sure you just multiply the 1 1/4 by 3 because if 1 1/4 makes 10 muffins you need to make 3 more dozens so 1 1/4 times 3 equals 3.75
