# Question #80bc9

Jan 8, 2017

Sand is $3 per bag and pea gravel is$4 per bag.

#### Explanation:

This is an example of solving two equations in two unknowns. Each purchase must be "translated" into an equation:

If we use X for the sand and Y for the pea gravel, the two purchases can be written as

$4 X + 3 Y = 24$ and

$2 X = 6$

The second equation simplifies (divide each side by 2) into

$X = 3$

so, sand is $3 per bag. Now, place this value into the other equation: $4 \left(3\right) + 3 Y = 24$$12 + 3 Y = 24$(subtract 12 from each side to "collect like terms") $3 Y = 12$$Y = 4$Pea gravel is$4 per bag.