Please help! Will mark brainliest!

Answer:
a = 1/2b
b = 2a
Step-by-step explanation:
-3a + 6b = a + 4b
Add -a and -6b on both sides.
-3a - a = 4b - 6b
-4a = -2b
Divide both sides by -4.
a = -2/-4b
a = 1/2b
To find b, multiply both sides by 2.
2a = b