Since an equilateral triangle has all three sides equal in length, we can equate the expressions for the measures of the two sides:
3x + 15 = 7x - 5
Subtracting 3x from both sides:
15 = 4x - 5
Adding 5 to both sides:
20 = 4x
Dividing both sides by 4:
x = 5
Substituting this value back into either of the expressions for the measures of the sides:
3(5) + 15 = 30
Therefore, the measure of the third side of the equilateral triangle is 30 inches.
The answer is d. 30.
the measures of two of the sides of an equilateral triangle are 3x+15 inches and 7x-5 inches. what is the measure of the third side in inches?
a. 5
b. 1
c. 18
d. 30
1 answer