Explanation:
6ft² of grass sod + 5 geraniums = $27
9 ft² of grass sod + 11 geraniums = $51
Let x represent 1ft² of grass sod.
Let y represent 1 geranium.
We have 6x + 5y = $27.
=> 1.5(6x + 5y) = 1.5 * $27, 9x + 7.5y = $40.5.
9x + 11y = $51
- (9x + 7.5y = $40.5)
=> 3.5y = $10.5, y = $3.
Therefore 6x + 5($3) = $27,
6x + $15 = $27, 6x = $12, x = $2.
Hence 1ft² of grass sod costs $2
and 1 geranium costs $3.