Question

rut gon

a, -(3x+1)^2-2(3x-1)(1+3x)

b,(a+b-c)^2-(a-b+c)^2+2(6-c)^2

Answer 1

\(-\left(3x+1\right)^2-2\left(3x-1\right)\left(3x+1\right)\)

\(=\left(3x+1\right)\left(-3x-1-6x+2\right)\)

\(=\left(3x+1\right)\left(-9x-1\right)\)

\(=-27x^2-12x-1\)

b/ \(\left(a+b-c\right)^2-\left(a-b+c\right)^2+2\left(6-c\right)^2\)

\(=\left(a+b-c-a+b-c\right)\left(a+b-c+a-b+c\right)+2\left(6-c\right)^2\)

\(=\left(2b-2c\right).2a+2\left(c^2-12c+36\right)\)

\(=4ab-4ac+2c^2-24c+72\)