What’s a equivalent expression for 4(x -2+y)

Can some one explain how to slove specifically, what is the value of x? 0.9(x+1.4)-2.3+0.1x=1.6 enter the answer as a decimal in the box. x= ?

The sum of the squares of two numbers is 8 . the product of the two numbers is 4. find the numbers.

Find the distance between the pair of points a(-1,8) and b(-8,4)