
Ari R. answered 04/28/21
SAT and ACT Tutor - All Sections
Two unknowns (A and B), so we need two formulas.
A - B = 3
A2+ B2 = 25.
The formulas are in different forms, so use substitution.
(B+3)2 + B2 = 29
B2 + 3b + 3b + 9 + B2 = 29 = 2B2 + 6b + 9 = 29
Set equal to 0 to solve: = 2B2 + 6b -20 = 0
factor out a 2. 2(B2 + 3b - 10)
C is negative, so the factors are opposite signs.
2(b+5) (b-2) Let's take the positive solution b= 2 A -B = 3. so A = 5