Question

The legs of an isosceles triangle have lengths x + 1 and -x + 7 . The base has length 3x - 3. What is the length of the base?

A. 4
B. 6
C. 3
D. cannot be determined

Answer 1

The legs of an isosceles triangle should have the same length by definition

Answer 2

first, set it up so that:
x+1=-x+7
then add x to both sides:
2x+1=7
subtract 1 from both sides:
2x=6
solve for x by dividing both sides by 2:
x=3

Answer 3

since we know that x=3, substitute 3 in for 3 for the base