17.
2x + 3x + 4(x - 2) use distributive property a(b - c) = ab - ac
= 2x + 3x + 4x - (4)(2) combine like terms
= (2x + 3x + 4x) - 8
= 9x - 8
Answer: d.
18.
The formula of a perimeter of a rectangle:
P = 2(l + w)
l - length
w - width
We have:
l = 4x + 5
w = 2x - 1
Substitute:
P = 2(4x + 5 + 2x - 1) combine like terms
P = 2[(4x + 2x) + (5 - 1)] = 2(6x + 4) use distributive property
P = (2)(6x) + (2)(4)
Answer: P = 12x + 8
