Assuming the pilcrow is supposed to represent pi:

100
If you want to multiply (2*x + 5) and (2*x - 5), you can do this using the following steps:
(2*x + 5) * (2*x - 5) = 4*x^2 - 10*x + 10*x - 25 = 4*x^2 - 25
The correct result is 4*x^2 - 25.
Answer:

Step-by-step explanation:
Given the ratio
5 m : 20 m ← divide both parts by 5
= 1 : 4
=
← as a fraction in simplest form
B = block p = park
2b + p = 10 min 2 runs around the block takes 10 minutes
2b + 3p = 22 min 2 runs around the block plus 3 runs around the park takes 22 minutes
To solve, I will use substitution. First, I will divide the first equation by 2 to get b by itself and subtract p from both sides to get b by itself. Then, substitute 5 - 1/2p in for b in the second equation because they have equal values. Then, subtract 10 from both sides to eliminate it. Divide by 2 to both sides to get 'p' by itself.
2b + p = 10 min ---------→b + 1/2p = 5 ----------→ b = 5 - 1/2p
2(5 - 1/2p) + 3p = 22 ---------→ 10 -p + 3p = 22 --------→ 10 + 2p = 22
10 + 3p = 22 ----------→ 2p = 12
2p = 12 -------------→ p = 6
It takes 6 minutes to jog around the park
Hope this helps!
I'm still doing the rest but number 1 is D