Answer:
Explanation:
Combine like terms: Like terms have same variable with same power and to combine the like terms, add/subtract the co efficient of the variables.
Perimeter:
Perimeter = sum of all sides
a) Perimeter of ΔABC = AB + BC + CA
= x + 14 + x + 14 + x + 14
= x + x + x + 14 + 14 + 14 {Combine like terms}
= 3x + 42
b) EF = DI - GH
= 2x + 3 - x
= 2x - x + 3
= x + 3
c) FG = HI - ED
= 12 + 2x - (x + 5)
= 12 + 2x - x - 5 {To open the brackets, (-1) is distributed to x and 5}
= 12 - 5 + 2x - x
= 7 + x
d) Perimeter of DEFGHI = DE + EF + FG + GH + HI + ID
= x + 5 + x + 3 + 7 +x + x + 12 +2x + 2x + 3
= x +x + x + x + 2x + 2x + 5 + 3 + 7 + 3 + 12
= 8x + 30