Browse · MATH Print → jmc algebra intermediate Problem If x is a real number, find (x+1)2+2(x+1)(3−x)+(3−x)2. Solution — click to reveal Let a=x+1 and b=3−x. Then, (x+1)2+2(x+1)(3−x)+(3−x)2=a2+2ab+b2=(a+b)2=(x+1+3−x)2=42=16. Final answer 16 ← Previous problem Next problem →