how to solve the following equation by substitution method :3x+4y=-6 ;3x-y=9 Share with your friends Share 0 Varun.Rawat answered this The given equations are :3x + 4y = -6 .....13x - y = 9 .....2Now, we will calculate the value of one of the variable in terms of another variable.From 1, we getx = -6-4y3Now, put the value of x in 2, we get3 × -6-4y3 - y = 9⇒-6-4y-y = 9⇒-5y = 15⇒y = -3Now, x = -6 + 123 = 2 0 View Full Answer Vishu Sharma answered this let 3x + 4y = -6 be equation 1 & 3x - y = 9 be equation 2 now ,In equ. 2 3x - y = 9 - y = 9- 3x y = - 9+ 3x Now ,putting the value of y in equ.1 3x + 4(-9 +3x)= - 6 3x - 36 + 12x= -6 15x - 36= -6 15x = - 6 +36 15x = 30 x = 30÷15 x = 2 Now, putting the value of x in equ.2 3(2) - y = 9 6 - y = 9 -y = 9 - 6 -y = 3 y = -3 hence, the valve of x = 2 y = -3 Done substitution method. -1
