x(x –9) + (x + 7)² 3b² – (a – 7b)²
x^2-9x+(x^2+14x+49) 3b^2 - (a^2-14ab+49b^2)=
x^2-9x+3b^2*x^2+42b^2* x +147b^2-a^2+14ab-49b^2
x(x –9) + (x + 7)² 3b² – (a – 7b)²
x^2-9x+(x^2+14x+49) 3b^2 - (a^2-14ab+49b^2)=
x^2-9x+3b^2*x^2+42b^2* x +147b^2-a^2+14ab-49b^2