\(a)\)\(64x25+35x25+25\\ =25x\left(64+35+1\right)\\ =25x100=2500\)
\(b)\)\(58x42+32x8+5x16\\ =58x42+16x2x8+5x16\\ =58x42+16x\left(2x8+5\right)\\ =58x21x2+16x21\\ =21x\left(58x2+16\right)\\ =21x132=2772\)
a: =25x(64+35+1)=25x100=2500
b: \(=58\cdot42+16\left(16+5\right)=58\cdot42+8\cdot42=42\cdot66=2772\)
\(a.=25\times\left(64+35+1\right)=25\times100=2500\)
\(b.=58\times42+\left(32\times8+5\times2\times8\right)\)
\(=58\times42+\left(32\times8+10\times8\right)\)
\(=58\times42+\left[\left(32+10\right)\times8\right]\)
\(=58\times42+42\times8=42\times\left(58+8\right)=42\times66=2772\)
4 và 5
