2(21+4x)=10x+1442+8x=10x+1410x-8x=42-142x=28x=14
(21+4X)*2=14021+4X=704X=70-21=49X=49/4=12.25
(21+ 4x)×2=10x +1442+8x=10x+1410x-8x=42-142x=28x=14