Question

a) y nhân 3 cộng y nhân 12,5 = 825 

b) y nhân 3 cộng y chia 0,5 = 12,85

Answer 1

\(a)y\times3+y\times12,5=825\)

\(\Rightarrow y\times\left(3+12,5\right)=825\)

\(\Rightarrow y\times15,5=825\)

\(\Rightarrow y=825:15,5\)

\(\Rightarrow y=5\frac{10}{31}\)

Answer 2

\(b)y\times3+y:0,5=12,85\)

\(\Rightarrow y\times3+y:\frac{1}{2}=12,85\)

\(\Rightarrow y\times3+y\times2=12,85\)

\(\Rightarrow y\times\left(3+2\right)=12,85\)

\(\Rightarrow y\times5=12,85\)

\(\Rightarrow y=12,85:5\)

\(\Rightarrow y=2,57\)