Question

5. (- 20 -b + 3c)^2​

Answer 1

2×-20 =-40

2×-b=-2b

2×3c=6c

so your answer is -40-2b+6c

Answer 2

Answer:

400+b^2+9c^2+40b-6bc-120c

Step-by-step explanation:

(a+b+c)^2= a^2+b^2+c^2+2ab+2bc+2ca

Thus, (-20+(-b)+3c)^2= (-20)^2+(-b)^2+(3c)^2 +2(-20)(-b) + 2(-b)(3c) + 2(3c)(-20)

=400+b^2+9c^2+40b-6bc-120c