Question

If 1 is added to a number and the sum is tripled, the result is 15 more than the number.find the number

Answer 1

$(x+1)\cdot 3=x+15\\ 3x+3=x+15\\ 2x=12\\ x=6$

Answer 2

Equation: 3( 1+x)=x+15

First you need to distribute the left side of the equation.

3+3x=x+15

Now you need to cancel out like terms. You can subtract 1x from both sides first and that leaves you with 3+2x=15. Then you will need the subtract 3 from both sides and that gives you
2x=12. Now you need to divide 2 from both sides and that gives you the final answer of x=6