Question

if (a+b) = 7 and ab = 20 , find the values of (a²+b²)
plzz reply with methods​

Answer 1

Answer:

9

Step-by-step explanation:

(a+b)^2=a^2+b^2+2ab

7^2=a2+b2+2*40

a2+b2=49-40=9

Answer 2

1. $a ^{2} + b {}^{2} = (a + b) {}^{2} - 2ab \\ \\ =( 7) ^{2} - 2 \times 20 \\ \ \\ = 49 - 40 \\ = 9$