Question

Question 7
If 2x + y = 23 and 4x – y = 19, then find the values of 5y – 2x and $\frac{y}{x}$- 2

Answer 1

Given equations are
2x + y = 23
and 4x – y = 19
on adding both equations, we get
6x = 42 $\Rightarrow$ x = 7
Put the value of x in E1. (i), we get
$\Rightarrow 2\left(7\right)+y=23\Rightarrow 14+y=23\Rightarrow y=23–14\Rightarrow y=95y–2x=5\times 9–2\times 7=45–14=31and\frac{y}{x}-2=\frac{4}{x}-2=\frac{9}{7}-2=\frac{9-14}{7}=-\frac{5}{7}hence,thevaluesof(5y-2x)and(\frac{y}{x}-2)are31and\frac{-5}{7}respectively$