Step-by-step explanation:
f(x) = x² - 4
y = x²-4
x = y²-4
x + 4 = y²

Answer:
Missing length = 20
Step-by-step explanation:
Ratio is 16/20=4/5
25×4/5=20
Combine like terms. The 5x is grouped to the 8x and the -7 isgrouped with the -55.
This means 5x + 8x = 13x and -7 - 55 = -62
The new expression is 13x - 62. We can't find the exact value of x because the expression wasn't set equal to anything.
1+1+1+1+1+5+5+5+5 is one
5+5+5+1+1+1+1+1+1+1+1+1+1 is another
5+5+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1 is three
5+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1 is four.
There are 4 combinations.