So firstly, you want to foil - (7v^4 + 6) [Think of the minus sign as -1]:
Next, combine like terms and your answer will be:
I am not that really sure but ig its 5
The answer is
RS=3 x 2 + 1, ST= 2 x 4 -2, RT= 64, i'm sorry if it didn't help
6(2x-8y=-24)
-2 (6x+4y=68)
12x-48y=-144
-12x-8y=-136
-56y=-280
-280÷-56=5
y=5
2x-8 (5)=-24
2x-40=-24
+40. +40
2x=16
16÷2=8
×=8
y=5
x=8
hope this helps, if needed a picture for better understanding,please comment.