Question

2x+y=35;3x+4y=65 solve by using cross multiplication method

Answer 1

$\textbf{Given:}$

$\text{Equations: 2x+y=35 and 3x+4y=65 }$

$\textbf{To find:}$

$\text{Solution of given sysytem of equations}$

$\textbf{Solution:}$

$\text{The given equations can be written as}$

$2x+y-35=0$

$3x+4y-65=0$

$\text{By Cross multiplication rule, we get}$

$\dfrac{x}{1(-65)-4(-35)}=\dfrac{y}{3(-35)-2(-65)}=\dfrac{1}{2(4)-3(1)}$

$\dfrac{x}{-65+140}=\dfrac{y}{-105+130}=\dfrac{1}{8-3}$

$\dfrac{x}{75}=\dfrac{y}{25}=\dfrac{1}{5}$

$\implies\dfrac{x}{75}=\dfrac{1}{5}\;\text{and}\;\dfrac{y}{25}=\dfrac{1}{5}$

$\implies\,x=\dfrac{75}{5}\;\text{and}\;y=\dfrac{25}{5}$

$\implies\bf\,x=15\;\text{and}\;y=5$

$\therefore\textbf{Solution is x=15 and y=5}$

Find more:

Solve each of the following systems of equations by the method of cross-multiplication:

ax + by = a²

bx + ay = b²

https://brainly.in/question/15918815

Solve each of the following systems of equations by the method of cross-multiplication:

a²x+b²y=c²b²x+a²y=a²

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Answer 2

This can solved by all three methods :-

•substitution

•elimination

•cross multiplication

So by substitution method it can be solved as:-

Solution is in attachment.