Can anybody do this for me please hurry EVERY answer MUST have an equation to go with it

The isosceles triangle has two sides of equal length, a, that sre longer than the length of the base ,b. the equation 2a+b=15.7 can be used to find the sides length. if one of the longer sides is 6.3 centimeters what is the length of the base

What is the measure of ac? 5 units 13 units 26 units 39 units

For each sentence below, find the value of x that makes each sentence true. (515) 5 = 25* x= (813)2 = 4* x=