What number must be placed in the box in the equation below to produce an equation that has more than one solution:\(5u + 3(4u - 6) = -3u - 27 + 20u + \boxed{\phantom{2}}?\)

Nvm it was 9

Let us simplify the guests answer, first expand the equation to get

5u+12u-18=-3u-27+20u+? = 17u-18=17u-27+?, subtract 17u so that -18=-27+?, add 27 to both sides so that

?=9, so \(9\)