Question 505605
Let 
Number = x

1) fifteen more than two thirds of a number is thirty.
2/3 (x) + 15 = 30
2x/3+15=30
Multiply by 3 
3*(2x/3+15)=30*3
2x+45=90
2) two times the sum of five times a number and three.
2*(5x+3)
=2(5x+3)