Step-by-step explanation:
let width = w then length, l = 2w + 6
[tex]2w + 2(2w + 6) = 120[/tex]
a rectangular garden has two pairs of equal parallel sides 2w and 2l. here we multiply 2 by the width and 2 by the length which is given as 6 more than twice the width or 2w + 6. we then add these sides to get 120
[tex]2w + 2(2w + 6) = 120 \\ 2w + 4w + 12 = 120 \\ 6w + 12 = 120 \\ 6w + 12 - 12 = 120 - 12 \\ 6w = 108 \\ \frac{6w}{6} = \frac{108}{6 } \\ w = 18[/tex]
check
[tex] width = w = 18\\ length \: l = 2w + 6 = 2(18) + 6 = 42\\ w + w + l + l = 120\\ 2w + 2l = \\ 2(18) + 2(42) = \\ 36 + 84 = 120[/tex]