Evaluate d − f if d = 7 and f = −15

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= ?

Simplify. 3(4+4x) (type your answer in with no spaces)

Given abc find the values of x and y. in your final answer, include all of your calculations.