Question

if a+b=7 and ab=17 find a^2-ab+b^2

Answer 1

Answer:

-2

Step-by-step explanation:

a+b=7

by using identity, (a+b)^2=7^2

a^2 +2ab+b^2=49

since ab=17, a^2+2*17+b^2=49

a^2+b^2=49-34

a^2+b^2=15

therefore, a^2-ab+b^2=15-17

= -2