Answer:
(1/21)(21×5^(x+2)-4×5^2x)
Step-by-step explanation:
5^(x+2)-4×5^x÷21×5^x
= 5^(x+2)-4×5^2x/21
= 1/21(21×5^(x+2)-4×5^2x)
-9
Replace x with -7 in the expression:
x^2 + 5 / x + 1
-7^2 + 5 / -7 + 1
49 + 5 / -6
54/-6
simplify the fraction
9/-1 = -9
4th option is correct.
look at the picture i sent
