We are given the following equation:
[tex]21-7\Delta=4-8\Delta[/tex]We need to solve for delta, to do that we will first add 8delta on both sides:
[tex]21-7\Delta+8\Delta=4-8\Delta+8\Delta[/tex]Now we add like terms:
[tex]21+\Delta=4[/tex]Now we subtract 21 on both sides:
[tex]21-21+\Delta=4-21[/tex]Adding like terms:
[tex]\Delta=17[/tex]Therefore delta is 17
