Question

Tìm 3 số a,b,c biết:

\(\frac{a+1}{2}=\frac{b+2}{3}=\frac{c+2}{4}\)

và 3a - 2b + c = 105

Answer 1

\(\frac{a+1}{2}\)=\(\frac{b+2}{3}\)=\(\frac{c+2}{4}\)=>\(\frac{3a+3}{6}\)=\(\frac{-2b-4}{-6}\)=\(\frac{c+2}{4}\)=\(\frac{3a-2b+c+3-4+2}{6+-6+4}\)=\(\frac{105+3-4+2}{4}\)=26,5

=>a=26,5.2-1=52

    b=26,5.3-2=77,5

     c=26,5.4-2=104

chắc chắn đúng

-duc tuan nguyen-

Answer 2

=>( 3a + 3 ) / 6 = ( 2b + 4 ) / 6 =( c + 2 ) / 4

= ( 3a + 3 - 2b - 4 + c + 2 ) / ( 6 - 6 + 4 )

= 106 / 4 

= 26,5

=> a + 1 = 53 => a = 52

=> b + 2 = 79,5 => b = 77,5

=> c + 2 = 106 => c = 104

Answer 3

vì \(\frac{a+1}{2}=\frac{b+2}{3}\)

\(\Rightarrow\)\(3a+3=2b+4\)

\(\Rightarrow\)\(3a-2b=1\)

\(\Rightarrow\)\(1+c=105\)

\(\Rightarrow\)\(c=105-1\)

\(\Rightarrow\)\(c=104\)

mà \(\frac{a+1}{2}=\frac{c+2}{4}\)

\(\Rightarrow\)\(\frac{a+1}{2}=\frac{53}{2}\)

\(\Rightarrow\)\(a+1=53\)

\(\Rightarrow a=53-1\)

\(\Rightarrow a=52\)

mà \(3a-2b=1\)

\(\Rightarrow3\times52-1=2b\)

\(\Rightarrow156-1=2b\)

\(\Rightarrow155=2b\)

\(\Rightarrow155\div2=b\)

\(\Rightarrow78.5=b\)

\(\Rightarrow b=78.5\)

Answer 4

sorry 

ghi nhầm nha

\(b=77.5\)