Use mental math to simplify each expression
1. 36+12+4
2.19.2+0.6+12.4+ 0.8
3.2•16•10•5
4.12•18•0•16

1)  36+12+4=40+12=52
2)  19.2+0.6+12.4+0.8=20+13=33
3)  2*16*10*5=10*10*16=100*16=1600
4)  12*8*0*16=0

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!