Answer:
x=84
Step-by-step explanation:
[tex]-\frac{1}{4}[/tex] x(x+8)+30=7
remove the parentheses
[tex]-\frac{1}{4}[/tex] x-2+30=7
calculate
[tex]-\frac{1}{4}[/tex] x+28=7
multiply both sides
-x+112=28
move the constant to the right
-x=28-112
calculate
-x=-84
change the signs
x=84