3 / 4 + 4 / 21 × 42 / 4
= 3 / 4 + 2
= 3 / 4 + 8 / 4
= 11 / 4
[tex]\it \dfrac{3}{4}+\dfrac{4}{21}\cdot\dfrac{42}{4}=\dfrac{3}{4}+\dfrac{4\cdot21\cdot2}{21\cdot4}=\dfrac{3}{4}+\dfrac{4\cdot2}{4}=\dfrac{3}{4}+\dfrac{8}{4}=\dfrac{11}{4}=2\dfrac{3}{4}[/tex]
