Answer:
x=2 and y=1
Step-by-step explanation:
Add the two equations to remove "y" and solve for x:
4x+8y=16
6x-8y=4
________
10x=20
x=2
Plug x=2 into one of the original equations to get the value of "y":
4x+8y=16
4(2)+8y=16
8+8y=16
8y=8
y=1
Therefore, x=2 and y=1
Answer: The answer is 40 minutes.
Equation: If m is the total number of minutes it takes him to complete his homework, 30% of m is given by 0.3m. Since 30% was done in 12 minutes, we have 0.3m=12.