If a+b=−9, and a=30/b, what is the value of a^2+b^2? Select
A) 31
B) 21
C) 41
D) 61
E) 51
a^2 + b^2 should make you think of these formulas:   (a+b)(a+b) = a^2+b^2+2ab   We already know (a+b) = -9 and a*b = 30   (a+b)(a+b) = (-9)(-9) = a^2+b^2+2*(30)   a^2+b^2 = 81 - 60= 
<gadget id="calculator">81 - 60</gadget>
<output>21</output>
21   Answer : 21
<result>B</result>
If a+b=−9, and a=30/b, what is the value of a^2+b^2?