Question

Evaluate the following expression for n = -4 and r = 3.

7n - 6(3n + 3r) + 5(4n – 2r)

Answer 1

same thing as the other problem, just plug them in respectively.

Answer 2

the first thing you would do is distribute which would make it 7n - 18n - 18r + 20n - 10r then you would add all like terms together making 9n - 28r then you would substitute the numbers in making 9(-4) - 28(3) then you would solve for the final answer which would be -120.

Answer 3

there are 3 parts in this expression:
1. 7n
2. -6(3n + 3r)
3. +5(4n - 2r)

the first part would be:
7n = 7(-4)
= -28

for the 2nd and 3rd part, follow the PEMDAS rule:
Parenthesis, Exponents, Multiplication, Division, Addition, and Subtraction

solve first the one with parenthesis (2nd part):
-> -6 [3(-4) + 3(3)]
= -6(-3)
= 18 (that's positive)
next, solve the 3rd part:
-> 5 [4(-4) - 2(3)]
= 5(-22)
= -110
combine all parts -28+18-110 = -120