Question

Câu 1:

a, Tìm các số nguyên x, y biết: \(-\frac{4}{8}=\frac{x}{-10}=\frac{7}{y-1}\)

help!!

Answer 1

\(-\frac{4}{8}=\frac{x}{-10}=\frac{7}{y-1}\)

\(-\frac{1}{2}=\frac{x}{-10}\)

\(\frac{1}{-2}=\frac{x}{-10}\)

\(x=\left(-10\right)\div\left(-2\right)\times1=5\)

\(-\frac{1}{2}=\frac{7}{y-1}\)

\(\frac{-1}{2}=\frac{7}{y-1}\)

\(y-1=7\times2\div\left(-1\right)=-14\)

\(y=\left(-14\right)+1=-13\)

Vậy x = 5, y = -13

Answer 2

\(-\frac{4}{8}=\frac{x}{-10}=>8x=-4\cdot\left(-10\right)=40\)

\(=>x=40:8=5\)

\(\frac{5}{-10}=-\frac{1}{2}=\frac{7}{y-1}\)

\(=>y-1=7\cdot2=14\)

\(=>y=14+1=15\)

Vậy x = 5, y = 15.

Answer 3

x = 5

y = -13

tk nha

Answer 4

Ta có: \(-\frac{4}{8}=\frac{x}{-10}=\frac{7}{y-1}\)

​\(-\frac{4}{8}=\frac{x}{-10}\Rightarrow x=\frac{\left(-4\right)\cdot\left(-10\right)}{8}=5\)

Thay x=5 vào đẳng thức \(\frac{x}{-10}=\frac{7}{y-1}\) ta được:

\(\frac{5}{-10}=\frac{7}{y-1}\Rightarrow y-1=\frac{-10\cdot7}{5}=-14\Rightarrow y=-14+1=-13\)

Vậy x=5  ;  y=-13.