Answer:

Step-by-step explanation:
<u>Equation Solving</u>
We are given the equation:

It's required to solve the equation for D. All letters must preserve their capitalization.
We must isolate the letter D by removing from the left side all the terms and coefficients that surround it.
Adding 7:

Dividing by f:

Answer:
i think its possibly 4
Step-by-step explanation:
Answer: AB = 12.5, BC = 15
<u>Step-by-step explanation:</u>
Perimeter of ΔBCD = BC + CD + BD. Since it is an isoceles triangle, then BC = CD = BD. So, Perimeter of ΔBCD = 3BC
3BC = 45
<u>÷3 </u> <u>÷3 </u>
BC = 15
Perimeter of ΔABC = AB + BC + AC. Since it is an isosceles triangle with BC as the base, then AB = AC. So, Perimeter of ΔABC = 2AB + BC
2AB + BC = 40
2AB + 15 = 40
<u> -15</u> <u> -15 </u>
2AB = 25
<u>÷2 </u> <u>÷2 </u>
AB = 12.5