Question

Tim cac gia tri nguyen cua x biet

a,  Y=5x+9/ x+3

b, Tim cac cap so nguyen x , y thoa mai he thuc :

(2x-1).(y+4)
 

Answer 1

\(a,\) Ta có \(y=\frac{5x+9}{x+3}\)

Để \(y\) nhận giá trị nguyên thì : \(5x+9⋮x+3\)

\(\Rightarrow5\left(x+3\right)+9-15⋮x+3\)

\(\Rightarrow5\left(x+3\right)-6⋮x+3\)

\(\Rightarrow-6⋮x+3\)

\(\Rightarrow6⋮x+3\)

\(\Rightarrow x+3\inƯ_{\left(6\right)}\)

\(\Rightarrow x+3=\left(-6,-3,-2,-1,1,2,3,6\right)\) Máy tớ ko viết được ngoặc khép thông cảm nha

\(\Rightarrow x=\left(-9,-6,-5,-4,-2,-1,0,3\right)\)