A squirrel burrowed 10 holes in 8 minutes. How many holes could the squirrel burrow in 12 minutes?

15

Step-by-step explanation:

Fast and loose: To go from 8 to 12 minutes you're adding half the time (4 minutes). So it has time to burrow only half the holes in the extra time, so 5. Total, 10+5=15.

Crunching numbers: it's a simple proportion: from which, cross-multiplying you get

step-by-step explanation:

for exempl this   system of equations   y = x - 3

                                                                y = 2x - 5

look   the line : y = x -3     ( red)

                            the line : y = 2x -5 ( bleus)