Question

If 3d – (9 – 2d) = 51, find the value of 3d.

Answer 1

3d -(9-2d) =51
= 3d-9+2d = 51
=5d-9 =51
= 5d=60
d=60/5 = 12
 so 3d = 3*12 = 36

Answer 2

First you open up the brackets so the sign for 2d changes to positive. So it will look like 3d-9+2d=51 then u simply the 3d-9+2d that should give 5d-9=51. Then you add 9 to both sides of the expression 5d-9+9=51+9. That will be 5d =60 so you divide 5 on both sides to find the value of 1 d which is 60/5=12 then to find 3d you multiply the value of d by three so it's 12(3)=36