Question

What is the product of 1.5 and 2.8 is 4.2?

Answer 1

2.8 x +1.5 = 4.2 (x – 10) 
2.8 x + 1.5 = 4.2 (x – 10) 
28 x/10 + 15/10 = 42/10 (x – 10) 
28 x + 15 = 42 (x – 10) 
28 x + 15 = 42x – 420 
14 x – 405 = 0 
x = 31.07