Can I get some help on this problem, in detail please?

7 { 6 [ 8*( T - 6 ) +12 ] + 2* ( T + 11 ) } ^2

7 { 6 [ 8t - 48 + 12 ] + 2t + 22} ^ 2

7 { 6 [ 8t - 60 ] + 2t + 22} ^ 2

7 { 48t - 360 + 2t + 22} ^ 2

7 { 50t - 338 } ^ 2

Now, at this point do i do 50t ^ 2 - 338^2 (which is 114244)?

Then 7 { 50t^2 - 114244}

Then 350T^2 - 799708?

If thats not correct can someone help me fix this?

Then