Answer:
a. x = 7; b. 75
Step-by-step explanation:
Equilateral means all sides equal the same measurement
4x - 3 = 2x + 11
4x - 2x = 11 + 3
2x = 14
x = 7
Plug in x = 7 to any equation
4(7) - 3
28 - 3
25
Perimeter means add up all 3 sides
25 + 25 + 25
75