\(\frac{a}{b}=\frac{7}{12}\Rightarrow a=\frac{7}{12}b\)
\(\Rightarrow\frac{a+10}{b}=\frac{\frac{7}{12}b+10}{b}=\frac{3}{4}\)
\(\Rightarrow4\left(\frac{7}{12}b+10\right)=3b\)
\(\frac{7}{3}b+40=3b\)
\(3b-\frac{7}{3}b=40\)
\(\frac{2}{3}b=40\)
\(b=40.\frac{3}{2}=60\)
\(a=\frac{7}{12}.60=35\)
\(a+b=60+35=95\)
\(\frac{a}{b}=\frac{7}{12}\Rightarrow\frac{a}{7}=\frac{b}{12}\)
Đặt \(\frac{a}{7}=\frac{b}{12}=k\)
\(\Rightarrow a=7k\)
\(b=12k\)
Ta có: \(\frac{a+10}{b}=\frac{3}{4}\)
\(\Rightarrow4\left(a+10\right)=3b\)
\(4a+40=3b\)
\(\Rightarrow3b-4a=40\)
\(3\cdot12k-4\cdot7k=40\)
\(36k-28k=40\)
\(\left(36-28\right)k=40\)
\(8k=40\)
\(k=40:8\)
\(k=5\)
\(\Rightarrow a=7k=7\cdot5=35\)
\(b=12k=12\cdot5=60\)
Vậy a+b= 36 + 60 = 96
mk sửa dòng cuối cùng:
Vậy a+b = 35 +60 = 95
