Question

solve for x and y 3x+2y=7 ,x+2y =9

Answer 1

Assume 3x + 2y = 7 as Equation [1]

Assume x + 2y = 9 as Equation [2]

Subtract Equation [2] from Equation [1], You will get =>

(3x + 2y) - (x + 2y) = 7 - 9
3x + 2y - x - 2y = -2
2x = -2
x = -1

Substitute x = -1 in Equation [1]

3(-1) + 2y = 7
2y = 7 + 3
2y = 10
y = 5

Therefore x = -1 And y = 5

Answer 2

$\underline{\underline{\Huge{\textbf{Question:}}}}$

solve for x and y for the following Equations

$\begin{array}{cccccc}3x&+&2y&=&7&---[1]\\x&+&2y&=&9&---[2]\\\end{array}$



$\underline{\underline{\Huge{\textbf{Solution:}}}}$

$\underline{\huge{\textsf{Step-1:}}}$
Consider Equation [2]

$\begin{array}{ccccc}x&+&2y&=&9\\\end{array}$



$\underline{\huge{\textsf{Step-2:}}}$
Multiply with 3 on both sides

$\begin{array}{cccccc}3x&+&6y&=&27&---[3]\\\end{array}$



$\underline{\huge{\textsf{Step-3:}}}$
Do [3]-[1] to get value of y

$\begin{array}{cccccccc}&3x&+&&6y&=&&27\\&3x&+&&2y&=&&7\\-&&&-&&&-&\\&&&&4y&=&&20 \end{array}$

$\implies 4y = 20$

$\implies y = 5$



$\underline{\huge{\textsf{Step-4:}}}$
Substitute in [1] to get value of y

$\begin{array}{ccccc}3x&+&2(5)&=&7\\\end{array}$

$\implies 3x\: +\: 10\: =\: 7$

$\implies 3x\: =\: 7\: -\: 10$

$\implies 3x\: =\: -\:3$

$\implies x\: =\: -\:1$



$\blacksquare\: \textsf{The Value of x and y satisfying given set of Equation are \underline{\textbf{-1\: and\: 5}}\: respectively}$