Rearrange using 'change side, change operation'. When you move the 'sin' over to the other side of the equals sign, we do the opposite which is sin -1 (inverse sin).

sin x 4 = sin 75 ∘ 9 sin x = 4 × sin 75 ∘ 9 sin x = 0.429300. Do not round this answer yet. To calculate the angle use the inverse sin button on the calculator (sin 1).