Finding A Cost to Profit

8x is 160% more than 1289+2.22x

This implies that

8x = (1289 + 2.22x)(1.6)   simplifying, we have

8x = 2062.4 + 3.552x     subtract 3.552x from both sides

8x - 3.552x = 2062.4

4.448x = 2062.4     divide both sides by 4.448

x= 2062.4 / 4.448 = 463.6690647482014388  or about 463.67